Not afraid of hard work or a little stress to build a business before I'm 30.

Don't be afraid to negotiate!

Never be afraid to reach out and/or ask questions... you'll get a lot of valuable input!

I would not be afraid of a full rehab just make sure you get multiple bids from qualified general contractors.

My business partners best friend was the underwriter, from a financial point of view I really shouldn't have been able to buy this house in the first place, so part of me was afraid that if I didn't jump I would miss the opportunity altogether.

Lawyers will not give referrals they are afraid of being sued more than you.   

I am also afraid of the rapid appreciation of homes relative to median incomes in the area and current economic conditions.

Do NOT use CA's TOD deed ( which could be used on CA property only) as it has issues: the title companies are afraid of it because it is new and attorneys do not like it as it cuts them out of the process.Being a CA resident, you will be taxed on assets from outside of CA. 

----In the worst case we sell at 300k (brand new apartment 2bed/2bath 850sqft + 200sqft) we still make some good profit.What I'm not sure is about the market - i'm just afraid of keeping some unused land when the market would crash very soon.I welcome and appreciate your thoughts.

That being said, you are the one taking the risk, not him, so don't be afraid to try to beat him up on price because he gets to walk away once he's paid, you do not.