I do own a small software business but I'm not really here to promote (especially since this isn't the place) so I'll leave those details out.

I have done short term many times but obviously screen closely as they don’t have a lot invested and you want it near perfect when they leave.

One side is month to month and I was going to leave it as such because I hoped someone would buy it and live in one side and rent the other. 

That will leave that amount more each month for you to save and lead to more investments. 

I refuse.. flat out.. that stops them in their tracks.. then I tell them we have first American  Fidelity WFG  TIcor Chicago take your pic I have closers at each that you just send the docs there and you know my files skinny as they are I can pop in sign in 5 minutes and leave.. they run that up the flag pole and will comply.I fell for the mobile notary one time in NYC when I was at my daughters wedding and that cost me 350 bucks I about came unglued on that one.. never again nothing against those folks but I have all those title companies on one street 5 minutes from my home base.. and I know all the senior closers on first name basis so for ME and I know I am not one off but that's how I do it..   

Or you’re leaving the debtor with a pile of cash they’ll have to deal with in BK.

Do I have them vacated at closing and replace with higher paying tenants, or do I leave them in there for a little while I get my feet under me?

Better trust leads to better communication and a smoother transaction, leaving me more time to go get the next deal.

I worry it'll be difficult to fill if/when the current tenants leave, and if it does flood again, I worry it'll be impossible to sell without taking a loss (thus wiping out any cash-flow gains).What are your thoughts?

So your deal/value add would need to be significant in order to get your seed funds back out and leave the required 20% in.