Is the initial deposit applied to the eventual money needed for down payment? 

And she’d get a discount as some of the sales money would come back to her. 

This is a lot less money than if she were to sell to  a homeowner. 

All you have to do is call, tell them you don't want to deal with court, and negotiate to refund some of the money to make them go away.

Stock market....you can loose 25% or more of your money in one day.   

I was wondering if I should use my own money or maybe use the rental equity instead... or there's even a better option.

If you are planning on doing anything more than a cosmetic flip, buying a property that has already been gutted to the studs saves you time and money. 

Is it feasible to obtain a loan or a good old boy agreement where a lender offers 100% financing for both the purchase price and construction costs at hard money rates, secured by a second position on the borrower's other properties?

I wasn't able to have much success with the software for moving my deals, but they did make an exception and I was able to get my money back after a short time of trying to move a few deals.

Telling people it makes a lot of money doesn't mean anything to a real investor.