IB Employment Opportunity - Questions and Seeking Advice

My thanks upfront to anyone on the forum who can answer some of my questions.

Background:

I have spent the last 13 years since '94 working in some shape or form within the IT Industry. 5 years ago I joined a F50 IT Vendor - headhunted into Asia to drive Strategic Bus Dev then asked to come to the CorpHQ and do a similar global role and since then have continued to significantly grow my responsibilities. My package is $500K USD 40% Base/Benefits, 60% Stock + Bonus.

The Opportunity: I am in the early stages of discussions with some European Investment Banks both big guys and boutiques who are interested in chatting with me to come over and drive (1) Turnaround activities -> Private Equity Buyout (2) Regional/Global Expansion (2nd round/IPO and post IPO or Note)(3) Private Equity Acquisition -> streamlining/expansion -> resale. This is something that greatly interests me.

Questions: 1. What specific questions should I ask the interested VCs/Investment Banks 2. What is an appropriate package mix for this type of engagement - Base vs Stock vs Bonus etc ? 3. What other 'soft' asks can I make eg. Signon bonus, relocation etc. I will be losing close to $200KUSD in stock that hasnt vested by making the shift. 4. What is the hierachy in such organisations ? Thought not a 'big titles' guy - which titles should I stray clear of and which ones are a good bet based on the realities of the role behind the title.

Thanks again for any insight and setting me straight where I am showing myself to be misguided moving into a new domain.