Giverny and Versailles cannot be done together. If you choose Versailles either have the museum pass or get tickets ahead (you can get tickets at FNAC and perhaps other places) You will have to stand in a long security line so get there about half an hour to 45 minutes before the place opens and you will be in the first group to go in. Since you have the ticket ahead you will then not have to get in the ticket line. This is ideally and all day trip: enjoy the chateau, then the gardens (there are restaurants at the foot of the gardens) and then head over to the Trianon and Hameau. There is a little train that will take you there if you like which is at the garden entrance by the chateau. (the ice cream kiosk at the exit of the gardens has really great ice cream -- I mention this because that is usually not the case with kiosks. I had really great rum raison glace here)
You should on arrival get a Navigo Decouverte. This will cover all your travel for the week except for the Orlyval which is massively annoying. It is only 30 Euro for a cab to anywhere on the left bank (35 to the right) so I would just go ahead and get a cab in to make things easier. The ND requires a postage size head shot; you can just print it off on your computer -- 25/30mm) The card is 5 Euro and the charge for the week is about 21 euro. It will take you anywhere in the Ile de France including Versailles and to the airport CDG when you leave. You can use it on the RER B. Those two trips alone pay for the card. The ND won't get you to Giverny as Vernon is in Normandy.
I loath the batobus and you like it -- so use your own judgment there. I am also not a hoho fan; it can be a good way to just move around seeing major sites, but it is not good transportation -- you wait forever for the things. I'd use the ND to zip here and there on bus or metro and then walk a lot in the area.
I have eaten at Morracan restaurants in Batignolles and in the Marais but can't advice if there is an area where they cluster. You can buy a nice roasted lamb head to go in the Chateau Rouge area FWIW.
If you will do several museums the pass will let you use special entrances at the Louvre, Orsay and Orangerie. The Louvre tends not to be a line problem if you enter through the Carousse. The problem is security not tickets; there are numerous ticket machines and manned kiosks under the pyramid once you get past security. I'd want to visit the Orangerie and the Orsay so the museum pass would be worth it to me.
In the evening. My husband is an amateur singer and so one evening we went to Belleville to an old touristy cafe called Le Vieux Belleville where people have dinner and then sing along with a chanteuse -- it is touristy but when we were there nearly all the tourists were French. We had a good time and the food was fine -- not a culinary experience but good standard food.
https://janettravels.wordpress.com/2011/10/09/le-vieux-belleville-non-je-ne-regrette-rien/
You should be able to tell from the snapshots whether this would be fun or too hokey for words.
Parisians tend to dine late and so you can easily book a nice restaurant for 8 pm and enjoy a leisurely dinner. There are some places with stunning rooms e.g. Bofinger, Le Train Bleu, Les Ombres and many traditional bistrots and brasseries (Rotonde and Coupole in Montparnasse are examples.) We also liked Chez Dumonet- Josphine which has lovely beouf bourguignon as well as classics like hanger steak and duck confit. They also have a really nice grand marnier souffle to share. After one of these nice meals plan to stroll back to the hotel. Paris streets are full of people at this hour and Paris is wonderful at night.
Some favorite evening strolls for me include around Notre Dame and along the river or up the Champs from Concord and across Pont Alexandre -- at the top of the hour you can see the Tower sparkle.
