100/sqft on a full gut sounds about right - This includes new roof, siding, windowns, electrical, framing, etc - basically everything besides foundation and structureFor a more cosmetic rehab with minimal expenses and alterations to electrical, plumbing, etc you are looking close to 50-60sqftFeel free to reach out anytime and I'd be happy to see your numbers and the project. 

Not only that but when you are in a portfolio loan and would like to for example sell one and break it out then most lenders will want to be paid back 120% of the balance attached to that piece of property back into the principle of the loan 

I've had Home Warranties, with A/C included, for about $550-$600.  

Unless you have a lot of money for a downpayment, it's highly unlikely you'll break even while living somewhere (especially in CA) unless you're willing to have a lot of roommates. 

This includes non-profits.  

If legal, is there anything specific that I need to include in the agreement other than the sale date and sale price to make it ironclad ?

So are you banking on appreciation of the asset while essentially just above breaking even when you're leveraged on the property? 

And then separate bank accounts for each LLC, I believe including each series.

I do not know of a BRRRR opportunity that doesn't have a life cycle that costs less than like 22k including all out of pocket expenses and that's if your purchase is around 75k - 90k.When I am setting up a market for my clients, first thing I do is call some agents in the market. 

Debt included.