I think you will get more answers if you move your question to this thread:
http://www.flyertalk.com/forum/franc...ber-paris.html
Or to this forum:
http://www.flyertalk.com/forum/ride-...uber-lyft-747/
I think most people don't tip Uber driver, because you have to tip in cash as the app does not have a tip option. I don't think Uber has a "van" option, at least not in the US. There are UberXL and UberSUV in the US and I don't know if those are available in Europe. They don't charge for extra passenger as long as everyone fit in the car type. You will get better answers from the above 2 links.