[Esel Mann]

As far as CDG, there is a T which goes from there right into Paris. No need to taxi.
I can't recall which major station it goes to: gare d'nord or gard d'est. Either way you would be good. My trip back in April we were on the TGV from Amsterdam. I did not come in by way of CDG. Additionally the T has cars which can accomodate say for example luggage beyond specticles, testicles, wallet, and watch. You will dependending need to stand watch.

Their T is superb to say the least. There are pickpockets on their T system like ours so keep your essentials near your jewels, that is to say front pockets. For major items, put such in the hotel's front desk safe, drop your room key off when you head out to explore, and no worries!

I would also recommend if you are doing Paris for more than say 2 days, skip the passes which may limit you (eg. 10-ticket passes). 30 Euro got (in April) a 5 day unlimited pass for Paris major. No hassles. I would check to see if that also gets you to/from CDG. If not, the round-trip to/from the airport passes are something in the 5 or 10 euros range. If you are staying at least part of the time in Paris for business, your company may have no problem springing for such passes.

Weekends are busiest for the major places to see. Weekdays would be the best time to go. If it blinks, winks, or makes you go oooo, or ahhhhh, any evening will have people, be patient.

Paris is a major metropolis. Lodging will be priced accordingly. Nevertheless, there are still reasonable deals. I would suggest instead of winging it you plan.
Additionally sometimes by extending your stay beyond what is needed for business, one can get a better flight price and many companies have no issue accomodating such. Some even spring for the added lodging.

As far as language barrier, like any other major Euro city, for example London, in the main tourist areas most everyone can speak enough English to assist. Once outside of that, YMMV and be prepared to at least try to speak their language. It's fun too! A dictionary can help. Just be wary of any Hungarian/English dictionaries.