Academic faculty expat experiences and advice

I have been offered a W1 professorship to start a research group (CS/Engineering) at a German university and am seeking to learn from others' experiences or someone prepared to be a second-opinion / sounding board outside of the offering institution. In particular, I am interested to hear about the following;

1. How much leverage did you feel that you have had to negotiate on the package? Granted, that would depends on the situation / competition. In my case, I learned that there was only one other viable candidate.
2. What did you try / succeed in negotiating in terms of support, resources and package (with respect to relocation costs (spouse, shipping etc) and language course).
3. In retrospect, what did you wish you tried to negotiate?
4. Any advice / experience on starting a research group. What would you have done differently? How did you expend your group? which grant schemes did you target? What did you focus on in the first couple of years?
5. How did you approach industry to seek partnerships / grants?
6. In my case the professorship is endowed by a large company, what conflicts did you encounter and how were they resolved?
7. Which academic committees would you recommend to sit on such that one gets sufficient exposure to how the institution works whilst the administrative load is low as to not impede on time for research?
8. What did you do to establish a specific culture in your group? Share resources, code, libraries, social etc
9. When and how did you start thinking / working towards the next step (e.g. W2)?
10. Did you encounter an expat bias?
11. Any specific cultural or professional dos and do nots?

Some of these questions are not Germany specific, so any advice will be greatly appreciated.