MF properties are more efficient to run for many reasons, but mostly because there is only one building, one roof, etc., to worry about.  

You need a lender who can close quickly and efficiently.

In regards to communicating with a RE agent, am I locked down to the amount that I specify to get a pre-approval for?

In my experience, the best bet is to try to make sure the HOA is running properly and efficiently, and let it do what needs to be done.

I tell people all the time to make sure you chose a CPA who is a good communicator.  

Great at follow-up, communication, and general customer service.

The key is communication.

Beyond that though, I find it far more efficient to have the deal in hand when asking for financing.  

I've also been communicating with a gentleman at First Citizens here in Charleston who helped one of my clients purchase an 8 unit last month and he's trying to structure some products for me, as well.

It looks like they're more efficient, and with mini splits, you can also be adding air conditioning at the same time.I found a local electrician who is going to inspect the radiant heat system for me and he can advise me on how urgent it is that I upgrade.