1. Go on a Wednesday
I would try to do this on a Wednesday, since this is the day in which both the Rodin Museum and the Louvre are open late. The former closes at 20h45, the latter at 21h45. This is to maximise the time available to get this trip done, thus reducing its time-criticality.
2. Reserve your Tickets
I can't stress this enough: reserve your ...
First of all, no backpacks allowed, no bags big enough to bring anything worth the effort.
Secondly, all bags going into any Paris museum are scanned and/or looked through, basically for bombs but a drone might stand out enough for the searcher to take note.
Thirdly, there are guards all through the museum and they will take action, and with Paris on ...
No Free Sundays April to September
First of all one must know that free Sundays have recently been suppressed from April to September. The Louvre website says:
Admission on Sunday
From October to March: access to the permanent collections is free for all visitors on the first Sunday of each month.
From April to September: no free admission on the first ...
The ticket must have been printed prior to your visit at least in principle, but it seems they may agree, at their own discretion, to print it for you if you have forgotten it (or claim to...). From the Terms and Conditions (the link is to the French version; the language can be changed using the list at the top-right corner):
The ticket must have been ...
Disclaimer: The Louvre is one of the most popular museum in the world, so there will be tons of people every day and every hours; just be patient, and if you miss something, don't worry, come back to it next time you are in Paris.
Don't go on Mondays, even if the museum is open, other Museums (municipal museums, like the Musée d'Orsay) in Paris are closed ...
There is a lot you asked and even more to answer so as gerrit suggested, you can separate questions.
1 and 3: Travelling
To come from Beauvais to Paris, you will have to take the 16 € bus which will let you in Porte Maillot.
Paris is very little, you can easily walk between attractions (except Montmartre).
You can use a ticket t+ for any metro, tramway, bus....
You can find almost everything about Louvre's permanent exhibits and events in the museum's site. Famous permanent exhibits that I'd personally wouldn't miss are:
The Winged Victory of Samothrace,
Nicolas Poussin's painting The Rape of the Sabine Women, and
Eugène Delacroix's painting July 28: Liberty Leading the People.
You can find more about the Louvre'...
Targeting Question 1:
You mentioned you're under 26 and you're travelling in the beginning of march. If you're in Paris on a weekend check out the "Ticket Jeunes Week-end". Unfortunately there is no english version of this site. It costs 3,65€ per day for zone 1-3. It was perfect on my last visit. To buy the ticket just head for the ticket office and ask ...
This answer applies only with a precondition.
If you can buy Louvre tickets in your hotel, do so. Then choose the pyramid entrance, ignore the entire queue and walk right up to the pyramid, where you can directly enter based upon your pre-bought tickets.
It says so on the link you've shared:
"Book tickets online
To avoid waiting in line, you can buy your tickets online.*
* Online ticketing service available in French, English, and Spanish.
Enjoy your visit!"
So the answer to your question is, YES, you can avoid the queues.
Timed tickets require you to enter within the stipulated window. That's how they ...
The Louvre admissions page says
18-25 year-old residents of the European Economic Area (EU, Norway, Iceland, and Liechtenstein) enjoy free admission to the museum year round.
Britain has not left the EU, so this would still apply to you. The page does not indicate how yoou demonstrate your residency (I can have a UK passport, but am not a resident) nor ...
Uffizi Gallery is an art gallery, mostly focused on italian art and with a special focus on Renaissance. I can't find the number of objects in the exposition, but it's probably the smallest of the three.
The Rijksmuseum is both an art, a craft and an history museum, meaning that its display of about 8000 objects include both works of arts (paintings, ...
Supposedly there's a smoke shop (tabac) in the Carrousel just a short walk from the Pyramid that sells tickets. Get your tickets there and skip the extremely long line at the Pyramid for non-ticket holders and get in the shorter (or non-existent) line for ticket holders.
France is a free country, so you can basically do as you please, and a flash mob shouldn't be an issue anywhere in a public setting.
However, if you want to stick to the letter of the law, this would probably be considered a public reunion, which may require authorisation from the "Préfecture". Also, the use of music in a public setting normally implies ...