I agree with Wayne Brooks, tons of red flags with this contractor. Remember that their are THOUSANDS of contractors out there, and only 1 of YOU.
Here are a few tips on choosing a contractor that you might want to consider:
1. Have a written and detailed budget before speaking with a contractor.
2. Get 3 bids for each section of your rehab (plumbing, electric, kitchen, baths, etc.).
3. Avoid paying contractors hourly!! (They refer to this as "time and materials" ....it's good for them and bad for you) Have them bid out the job for a flat rate (they can separate the materials out if you'd like). For example, if your kitchen budget is $4,000, get bids for the entire job (cabinets, counters, tile floor, etc).
4. Get everything in writing. You would never consider buying a house without a written contract, why would you go into a rehab project without a written contract from your contractors?
5. Avoid the "profit sharing" model. Let the contractor know that you reserve profit sharing for contractors who have proven themselves. If this guy is already asking for a cut of the profits on the first deal, imagine what he'll want 6 months from now!
I know that this stuff is tough to do, but please believe me when I tell you that you'll thank yourself later when things go well and you will want to pull your hair out when things go south.
Gary