Mainz Or Wiesbaden ? - Same Q -Different approach (Wiesbaden-Mainz)

Hello

Let me introduce myself quick - I am another anxious, potential transfer to Germany from USA, in January. Many thoughts are swimming in my mind and hopefully I can get help / input from some of you so that I can find my answers.

Situation: I work for an American auto company in USA. I have an offer from a German Auto Engineering company. I think it's a fair offer but my end of the day savings will be less than in USA because of taxes, living cost in Germany etc. It's fine though I am looking for the experience and trying out a new culture.

Questions:

1. Housing - Wiesbaden or Mainz ? I read through the forum and seems like there were mixed answers - Is Mainz cheaper or Wiesbaden cheaper in terms of apartments ? Does Wiesbaden have nicer apartments for similar price range as Mainz ?
Important: Do I always have to bring / buy my own kitchen ? Seems like either its fully furnished or nothing at all. Is it fairly common to find a place with just the Kitchen ? (Kitchens are expensive..blah :) ). I do own a house in USA and probably will bring furniture from here.

2. Social Life: I do like socializing and enjoying some night life. From the previous answers seems like Mianz is better in this aspect. Is the commute easy between Mainz and Wiesbaden in case I end up staying in Wiesbaden ?

3. Language: I really would like to be fluent in German but for the first few months I hope I can survive with English and my broken very basic German vocabulary. I know in the professional sector English is no problem but would some one please educate me if in everyday life - social, shops etc I can get by with English for the first few months ?

4. This is the anxious side of me speaking: Warn me if I shouldn't be doing this... :-) I still have time to turn around...ja..ja..

Thank you all for your time.