The flights are on the same ticket, so the airlines should make sure you can take all flight (else they are actively blocking you to fulfill the travel contract).

The EU right allow you to cancel the flight and get full refund, in case of delays (instead of compensation). This has few rules, but it should be better than flying and returning without exiting the airport. I think you should prefer such option, when you see that the outbound flight is so delayed.

Reimbursement and a return flight in the event of a long delay (5 hours or more) at departure

 

If your flight is delayed at least 5 hours at departure, the airline must reimburse your ticket and, if you have a connecting flight, offer a return to the airport of departure at the earliest opportunity.

If you have less then 5 hours, it could be tricky (but 2 hour meeting, 1 hour buffer on both arrival and departure, and some time to reach the meeting), this could be the case.

This answer the question in the middle of your text.

The main question is interesting, and it is difficult to tell. The EU regulation defines the final destination as:

‘final destination’ means the destination on the ticket presented at the check-in counter or, in the case of directly connecting flights, the destination of the last flight; alternative connecting flights available shall not be taken into account if the original planned arrival time is respected;

so in theory this final destination should be your home airport, but this will make most of the rules non-sense, and contrary to the purpose of compensations.

I think with long delay and short flights, you should ask at gates for alternative. I think in such case they could help more: It is their interest (with long delay, the probably outcome is to cancel the flight and to get people in the next flights [if there are several flights per day, like the case in the question], so having less passengers relives them from compensations and cost to other airlines.

ADDENDUM: It was marked very prominently and on the TOP on EU passenger right:

The outbound and return flights are always considered as two separate flights even if they were booked as part of one reservation. In some cases the airline operating the flight (also known as the operating air carrier) may not be the same as the one from which you bought your ticket. In case of any difficulties only the airline which operates the flight can be held responsible.

The flights are on the same ticket, so the airlines should make sure you can take all flight (else they are actively blocking you to fulfill the travel contract).

The EU right allow you to cancel the flight and get full refund, in case of delays (instead of compensation). This has few rules, but it should be better than flying and returning without exiting the airport. I think you should prefer such option, when you see that the outbound flight is so delayed.

Reimbursement and a return flight in the event of a long delay (5 hours or more) at departure

If your flight is delayed at least 5 hours at departure, the airline must reimburse your ticket and, if you have a connecting flight, offer a return to the airport of departure at the earliest opportunity.

If you have less then 5 hours, it could be tricky (but 2 hour meeting, 1 hour buffer on both arrival and departure, and some time to reach the meeting), this could be the case.

This answer the question in the middle of your text.

The main question is interesting, and it is difficult to tell. The EU regulation defines the final destination as:

‘final destination’ means the destination on the ticket presented at the check-in counter or, in the case of directly connecting flights, the destination of the last flight; alternative connecting flights available shall not be taken into account if the original planned arrival time is respected;

so in theory this final destination should be your home airport, but this will make most of the rules non-sense, and contrary to the purpose of compensations.

I think with long delay and short flights, you should ask at gates for alternative. I think in such case they could help more: It is their interest (with long delay, the probably outcome is to cancel the flight and to get people in the next flights [if there are several flights per day, like the case in the question], so having less passengers relives them from compensations and cost to other airlines.

ADDENDUM: It was marked very prominently and on the TOP on EU passenger right:

The outbound and return flights are always considered as two separate flights even if they were booked as part of one reservation. In some cases the airline operating the flight (also known as the operating air carrier) may not be the same as the one from which you bought your ticket. In case of any difficulties only the airline which operates the flight can be held responsible.

The flights are on the same ticket, so the airlines should make sure you can take all flight (else they are actively blocking you to fulfill the travel contract).

The EU right allow you to cancel the flight and get full refund, in case of delays (instead of compensation). This has few rules, but it should be better than flying and returning without exiting the airport. I think you should prefer such option, when you see that the outbound flight is so delayed.

Reimbursement and a return flight in the event of a long delay (5 hours or more) at departure

If your flight is delayed at least 5 hours at departure, the airline must reimburse your ticket and, if you have a connecting flight, offer a return to the airport of departure at the earliest opportunity.

If you have less then 5 hours, it could be tricky (but 2 hour meeting, 1 hour buffer on both arrival and departure, and some time to reach the meeting), this could be the case.

This answer the question in the middle of your text.

The main question is interesting, and it is difficult to tell. The EU regulation defines the final destination as:

‘final destination’ means the destination on the ticket presented at the check-in counter or, in the case of directly connecting flights, the destination of the last flight; alternative connecting flights available shall not be taken into account if the original planned arrival time is respected;

so in theory this final destination should be your home airport, but this will make most of the rules non-sense, and contrary to the purpose of compensations.

I think with long delay and short flights, you should ask at gates for alternative. I think in such case they could help more: It is their interest (with long delay, the probably outcome is to cancel the flight and to get people in the next flights [if there are several flights per day, like the case in the question], so having less passengers relives them from compensations and cost to other airlines.

The flights are on the same ticket, so the airlines should make sure you can take all flight (else they are actively blocking you to fulfill the travel contract).

The EU right allow you to cancel the flight and get full refund, in case of delays (instead of compensation). This has few rules, but it should be better than flying and returning without exiting the airport. I think you should prefer such option, when you see that the outbound flight is so delayed.

Reimbursement and a return flight in the event of a long delay (5 hours or more) at departure

If your flight is delayed at least 5 hours at departure, the airline must reimburse your ticket and, if you have a connecting flight, offer a return to the airport of departure at the earliest opportunity.

If you have less then 5 hours, it could be tricky (but 2 hour meeting, 1 hour buffer on both arrival and departure, and some time to reach the meeting), this could be the case.

This answer the question in the middle of your text.

The main question is interesting, and it is difficult to tell. The EU regulation defines the final destination as:

‘final destination’ means the destination on the ticket presented at the check-in counter or, in the case of directly connecting flights, the destination of the last flight; alternative connecting flights available shall not be taken into account if the original planned arrival time is respected;

so in theory this final destination should be your home airport, but this will make most of the rules non-sense, and contrary to the purpose of compensations.

I think with long delay and short flights, you should ask at gates for alternative. I think in such case they could help more: It is their interest (with long delay, the probably outcome is to cancel the flight and to get people in the next flights [if there are several flights per day, like the case in the question], so having less passengers relives them from compensations and cost to other airlines.

ADDENDUM: It was marked very prominently and on the TOP on EU passenger right:

The outbound and return flights are always considered as two separate flights even if they were booked as part of one reservation. In some cases the airline operating the flight (also known as the operating air carrier) may not be the same as the one from which you bought your ticket. In case of any difficulties only the airline which operates the flight can be held responsible.