2) Who will be working on my issues? (I bring this up because larger firms usually have associates do the actual grunt work.)
3) Given my situation, and my goals [which you will describe to them], what is the best structure for my company for (a) legal purposes? and (b) tax purposes?
4) Same as 3a) and 3b), but for you.
5) Ask them about IP issues. (You haven't provided enough info to provide a sample question.)
6) Ask them about employees/labor law issues, especially as it relates to co-founders, hiring your first employee, and compensation. (You haven't provided enough info to provide a sample question.)
7) Ask them about compliance/paperwork/etc. associated with maintaining the structure you will use. (It can very from a little to a lot.)
For example, most law schools will have in-house small business clinics, where law students, who are generally given special permission by the State Supreme Court to practice before being admitted to the Bar, provide free legal services under the supervision of a professor licensed in the State.