As with any product, if you can get folks who are interested, why not (not legal advice).
If I understand it correctly, in this structure you are basically financing the purchase, but not the rehab. In our market, the fix up costs are often higher than the purchase price for the home, so this product would not be super exciting. I realize that in most markets, that is not the case!
I may be missing a few details, but looks like your client would need over 50% of purchase price up front? Or, since the proof of funds list doesn't include down payment, are you getting that on the back end? Perhaps the 65% LTV is based on ARV, not purchase price?
My math: 35% down, (65% LTV), 5% for 6 mos rent (at 10% cap rate), 10% option fee, 1-2/3% for 2 mos' security (again, 10% cap rate-although not listed in proof of funds, so maybe not required over and above the 6 mos' rent required there?), so almost 52% cash upfront plus any fix up monies and 35% of $4k closing costs (yes, included in loan but still have the 65% LTV ceiling).
As a potential buyer, I would want to compare this to a hard money lender - this seems like a similar structure, but the (effective) lender holds the deed and isn't financing fix-up costs, which would make it less interesting to me.