One of the necessary documents for a Schengen visa for non EU citizens is proof of your flights, but it doesn't state the actual (e-)tickets (for which I already paid), or the reservation of flights.
So my question is, which option would be more acceptable (if I can provide any of them) to provide printed tickets to an EU member embassy or reservation of flights (reservation does not expect payment)?
for journeys undertaken for the purposes of tourism or for private reasons:
(b) documents relating to the itinerary:
— confirmation of the booking of an organised trip or any other
appropriate document indicating the envisaged travel plans,
— in the case of transit: visa or other entry permit for the third
country of destination; tickets for onward journey;
So the actual e-ticket is not required, and booking confirmation should be enough - as long as it indicates your travel plans. However if you already have an issued e-tickets which state your itinerary, they can serve as such indeed.