What are the monthly expenses?If you don t know the expenses, there is no way you could project the break-even and profitable sales points.
Leasehold or Freehold?. if its leasehold you need a solicitor to see the lease. Business rates, utility bills, profit loss. You need to see audited accounts for the last 3 years. There are loads of questions, if you have never run a business before do not do it.
Only 1 question worth asking: Can I have a look at your books? .Seriously - they can tell you anything. I wouldn t touch a business without looking at the books, preferably with an accountant. If they ve got nothing to hide, they won t have a problem with that.