I think it's very dependent on the property and market. 

Quote from @Mark Cruse: Quote from @Jay Hinrichs: Quote from @Mark Cruse: I'm not sure how many are being laid off in the DMV but depending on how many, how could it not lead to a barrage of negative impacts?

As others have mentioned, DSCR loans are generally for turnkey rentals (although outdated rentals may still qualify depending on the level of deferred maintenance). 

Looking at, and that depends on getting an 80% LTV on heloc/refi, at 600-650K 

Do you typically replace existing boiler systems with forced air or does it depend on the circumstances?

Depending on how big your portfolio is it might be more or less expensive for you.

Depending on where your place is there are parts of the county near SLT that do allow them. 

This is really going to depend on the state you are looking to do business in.

Its really hard to say it depends on a lot of things - My rule of thumb - especially when its higher than I think it should be, is to get at least 3 quotes.

Property management would depend on the company but ranges from 7-10% so interview a few different companies.