I would probably need to add 1 more room in the house (interior, no sqft add), add/change doors, bathrooms, ramps, handle bars, etc. that I think can easily run me 10K or so. 

If the property can support the debt easily I would go that route.  5 year balloons sneak up on you quicker than you think.

Usually easily managed from a distance and come in a wide range of size and quality.

An exceptions is an IRS lien but that is easily handled with proper notice.

You should understand the risk that you can easily get wiped out if the first position lender forecloses.

I could easily stick $40,000 to $50,000 into the house between siding, a new ac unit, hvac unit and everything else.

Because here you can easily blame the seller. rock on!

I'm a member of USAA and I have never considered using them for anything other than auto and home insurance along with standard banking.Many local banks have easily beaten their rates for auto loans and it looks like home loans as well. 

Frederick County does not have such a thing...but I could easily see Baltimore City or County having something similar to Montgomery County.

And after turning them around you can sell them easily at a lower cap rate.