Amend the way you are thinking about it, I think you mean what happens when the investor has 100% of his principal investment returned to him?

She also says that if he owes more than he's selling it for and if he doesn't have that money he will have to pay back my down money and anything paid to principal during the lease period.

That way a buyer can use that money as a contribution toward principal to make things less underwater.

Your gross income is your personal gross plus 75% rents-PITI.Take that number times 28% for a conservative, conforming coventional loan for PITI (principal, interest, taxes, insurance).28% of 7980 is 2234.

Also, when calculating estimated returns/cash flow, part of the mortgage payment is going to pay down principal, should this be considered in estimating returns as you are building up equity for yourself?

Principal reduction is a revenue event for you.

This will not remove you but you will know if you can get any principal reduction to get a little closer to market value which will open your options up.

Finally locked in a rate for the first property, 1,850 condo - 3bed/2bath @ 101k 25%down for 15 year loan. 560 Principal and Interest.

Talk to them now to extend the loan, a refi and see how much they will want to reduce the principal.

Otherwise it can get complicated as you really are putting buyers and sellers together, facilitating sales.You need to read your state statutes very carefully word for word as to what requires a real estate license and then don't do those things if you don't have a license.You can be an employee or memebr in a LLC that buys or sells, as a principal, in other words if BAC LLC buys a property and you are a memeber of BAC LLC, you can then be entitled to profits for the work you perform in that LLC.Another way is for you to take an option to buy and then sell your option, this is placing you in a position of havine an interest in the transaction, but those you sell to may have financing issues with this, it also depends on property restrictions or title limitations as beeing seen as sales during a restriction to conveyances, again check and see how these issues are viewed locally.Generally, you can not act as a third party between a buyer and seller and simply arrange or introduce deals and be paid a fee independly as that is a function of a real estate agent/broker.Lastly, it's easy to get a bad reputation amoung Realtors if you're known as a birddog, they will likely see you as unlicensened competiton and expect them to complain and report your activities.