Life / rellocation from Kiev to Warsaw [3]

Hello everybody, may be someone could help me:

1. Is it possible to find a good job only with fluent English (also Ukrainian, Russian)? At this moment I've only started to learn Polish but need to relocate in one month. I have a good experience in Project Management and Sales (4 years overall), so do I have any chances?

2. Is it a big problem for my future employer to give me job offer if I have only Shengen Visa with no permission to work?

3. Can I use my Ukrainian Driving license instead of getting Polish one?

4. Can I buy a car in Poland for myself and how to register it? (seems like for the first couple of months I will have only visa to Shengen Staten)

5. Medical insurance - is it expensive in Poland and how can I buy insurance for myself at least for 6 months?

Thanks for your answers :-)