@Daniel Brown If I was you I would let her know you are interested in REI so much that you would get the place rent ready ( She pays material your labor is free) "take over" as property management or something to that effect, Earn a little cash, learn from her and get on the job training.  

I even paid for the extra HVAC coverage. 

I found a potential property and I think that's where the "extra" square footage is coming into play (the house has 2 bedrooms and 1,100 SF).I'm assuming adding a bedroom here may be more complicated because of matching the siding on the house - probably not worth the cost but I'm not sure.Anyone have experience with something like this?

Or extra information like pay stubs, driver's license, etc.? 

Sounds like you bought a house, with taxes paid up for the quarter already and you took possession sometime during the quarter. it also sounds like they forgot to calculate the tax credit due to the seller at closing. if that's the case, I believe most purchase contracts have a clause that states you will make it right if there was some miscalculation or simple omission at closing. even if not, the old owner paid for taxes and you are benefitting unjustly. the ethical thing in my mind is to refund the extra tax. there is no reason to go to court for this.if i'm wrong, please explain the situation better.

(This year I made 40% return and 15% over 5 years so I did really well)3) My money in the market COULD keep earning above what I pay in interest?

Not impossible to work around or deal with, but will require some extra due diligence and awareness of what you are getting into.

Or if there's any questions that the tenant is getting an extra discount for mowing the lawn, or being a caretaker, or whatever reason. 

VA loans are a great benefit that our veterans have earned for their service. 

Be extra careful meeting 'strangers' in your home.