Paris for 8 days - Itinerary help wanted!

I have spent a great deal of time in Paris and this past January I did a solo trip to do some new things. My favorites from this trip were:
Seeing an Opera in the Palais Garnier Opera house, and I ordered champagne and macarons for the intermission to be my dinner that night.
The view from the outside viewing deck at Galeries Lafayette - had never been up there
A dinner cruise on Le Calife, a splurge to be sure, but the food was lovely and it was a full evening of entertainment watching the scenery
Dinner at Les Deux Magots followed by a concert at St. Germain des Pres (duck and profiteroles - make a list of things you want to eat while you are in Paris and make it happen)
Touring inside each church I passed during my walks, I like to sit and pray the Lord's Prayer. I heard some impromptu organ practices this way.
The Stein Picasso exhibit at the musee du Luxembourg. This has ended, but look for limited exhibits to visit which can make a repeat trip to a museum extra special.
Food shopping at the grand epicerie of the Bon Marche

And from previous trips, try a biking trip to Versailles if that is in your comfort zone. You get to shop for a picnic, ride all through the gardens and then tour the Chateau. Even if you have toured inside before, this would make it different for you.

We have different travel styles but I do have a couple of thoughts:

17 - If you are concerned about jet lag, you might look into the Timeshifter app. This tells you when to seek and avoid light/caffeine based on NASA science for astronauts on the Space Station. It worked really well for me a year ago and I will try it out again soon. The first RT is free for you to try it out. I liked it well enough that I'm paying for it this time.
21 - Rodin Museum? It's near-ish to the ET and his statues in the garden are awesome!
23/24 - What museums are you interested in? Some need timed entries so depending on which you choose you might do better just to pay for individual entries. I might do this earlier in your trip but I suspect you want to save the weekend for shopping? The museum pass is good for 24 hours from the 1st time you enter a museum, so if you entered a museum at 11A on the first day you could theoretically have until 1059 on the 3rd day to use it.

Sorry...not a shopper or flea market person so no advice for those areas!

Have you been to the Musee D'Orsay? It's my favorite museum in Paris, better than the Louvre IMO.

And the Musee de L'Orangerie, with Monet's gigantic water lily paintings!

And you can wander and relax in the Luxembourg Gardens.

Versailles is an easy daytrip.

We enjoyed a tour of the Paris Opera House.

Hope this helps.

WyoPrincess,
In Galeries Lafayette (yes, a large dept. store) look up at the beautiful ceiling. On the rooftop get a good view of Paris. It is also very close to the Opera Garnier, a beautiful (rococo?) building. I highly recommend a tour of the inside, and perhaps a show or concert there if possible.

In Montmartre on the steps of the Basilica of Sacre Coeur, look out over a good view of Paris from here as well. Go inside the church...only just over 100 years old but filled with beautiful mosaics. Very touristy and overpriced (IMHO) a show at the Moulin Rouge ( perhaps the cabaret you seek?)

Definitely the Rodin Museum. Go before visiting the Eiffel Tower. It's a shortish walk from one to the other. The sculptures in the gardens are wonderful. I go there every single time I am in Paris. Give the gardens 1-2 hours. You can also go inside his house. Interesting, but missable with a short time involved.
The one hour boat ride on the Seine by Vedettes de Pont Neuf (inexpensive, narrated, usually in French, sit up top for best views). Get there about 45 min. before your time. It's at one end of the Ile de la Cite. Don't know about speakeasy's. Did they come up on Trip Advisor, and were they sponsored? Sounds touristy and gimmicky to me, but I don't know.
In Reims don't miss the cathedral (great stained glass and it is the place where nearly every French king was crowned). Also while in Reims you can visit the Musee de Rendition, where the surrender by the Germans for WWII was signed. A nice little museum.
Do you mean bicycle all the way to Versailles from Paris, or bicycle within the grounds of Versailles? The former seems too far, and I don't know how scenic it would be. The grounds are huge, so a bicycle within them is a good idea. This would be a full day trip. No tour group necessary, but take an early train there and on return you could do the boat ride on the Seine.
Favorite free thing to do is walk along the left bank side of the Seine and check out the bouquinistes. Lots of secondhand books, posters, whatnots, etc. (not clothes). Classic French experience, and offering a good view of Notre Dame as well. Speaking of ND, it opens December 8. Be sure to see Ste. Chappelle. It is close to ND. That is a don't miss for anyone! They have concerts there too, if you want to spend a bit.
I don't know about the Museum Pass and its usefulness in your situation. Just be aware you need to make reservations for Versailles palace, Ste. Chappelle. Rodin and Opera Garnier, I don't know.
Giverny you can take the train on your own. I would also go early to avoid big crowds. A little bus goes from the train station to Monet's house (and back, coordinated with train times). This could be a half or three-quarter day trip, giving you a late afternoon free for whatever you want to do (show, concert, boat ride?)
You have lots of options. Just be sure to check everyplace you are considering to see if you need to reserve a time. Walk-ups are mostly a thing of the past. Have a wonderful time!

Definitely suggesting biking within the grounds of Versailles. Fat Tire bike tours though will let you meet in Paris, take you on the train, fit you up on a bike and lead you to the market to shop and then around the gardens. It's an easy way to do this if doing it all on your own in not in your comfort zone.

WyoPrincess,
Just fyi, Les Deux Magots restaurant, which Tigerfan mentioned, is celebrating its 140th anniversary this year. And the same family has owned it since 1914. It Is iconic...former habitues were Sartre, Hemingway, de Beauvoir and Picasso. Even Miles Davis, Paul McCartney and John Lennon went there. The New York Times ran an article about it today. It puts one in the mood for an aperitif there!
Amusez-vous bien!

Thank you, everyone! I have taken your suggestions and added opera, a dinner cruise and bike riding to the itinerary! Oh, and dinner at Les Magots! Thank you so much!!

In France 2nd hand and vintage stores are called "friperies". Sometimes they are kilo stores, where you can buy a kilo of stuff for a set price. There are a number of friperies on Rue de la Verrerie. This is not far from the Centre Pompidou and Hotel de Ville. There are also some good ones in Montmartre. Have fun!