But as I've accumulated more experience and assets, my situation has just become too complex for one spreadsheet. 

I get a lot of interest from younger people wanting to rent together.Thus far I have had very good luck with tenants and all have been room mate situations.

It is half situated on concrete slab and the other half is pretty much built on top of dirt (we think, we are unable to get to it) and I called the building department and there were no permits pulled.How should I go about negotiating down the price?

Good luck and remember, these can be very sensitive situations so look to help them first.I hope this is helpful

I have a neighbor offering me cash for a lease option to buy and/or assume our mortgage in 6 months (because they're in the middle of a divorce) but I thought I'd come on here because that situation seems like it could get sticky.

If it's baseboard electric heat and hot water, it's especially urgent to get this taken care of.Either way, I'd find a way to get a second meter installed pronto.

Has anyone ever dealt with this situation before?

Can anyone offer experience or advice in this situation? 

So on September 25, 2009 I wrote a letter to the lender and told them the situation.

@Alberto Ramirez you structure it for a win win win situation