The simplest way to get from the airport to your hotel is by taxi, which will cost 50 euros for up to four people. Taxis will be lined up at the terminal exit, don't accept rides offered inside the terminal. You could also take the RER commuter train to Chatelet, a big station near the Louvre, and then Metro to the station nearest your hotel, total cost 10.3 euros per person. But I'd suggest the taxi for that first jet-lagged morning with your luggage, especially if there are three or more of you.
If you land at 9 AM and check into your hotel by 11 you'll be very lucky. Deplaning, immigration, baggage claim if any, getting to ground transportation, and getting to the hotel will likely add up to more time. But maybe you'll be lucky or extremely efficient.
A HOHO bus ride will show you a lot of Paris streets and buildings, and take a long time. Instead, I'd suggest walking to sights near your hotel, and using the Metro and regular buses to get to places too far to walk to. A carnet of ten tickets would make sense. You can share the carnet, e.g. five tickets per person.
The Paris Pass is expensive and unnecessary. Depending on your sightseeing priorities, the Paris Museum Pass might make sense. It includes Versailles. What else to do in your limited time in Paris is best decided by you, based on your interests and energy level. Above left on this website, under "Explore Europe," you can find our host's suggestions for Paris sightseeing. They are good, but his priorities may not be yours. If I had only 3.5 days on my first visit to Paris (one of which would be jet-lagged), I would not go out to Versailles. There's more than enough for me in the city. But If Versailles means a lot to you, then go for it.
