If you have a specific property in mind, maybe call the inspectors office and get info on the process and what they are looking for when inspecting for a STR.You might be able to have one come out before the purchase to get their opinion.

I can plan for this if the tenant gives me a heads up ahead of time — which they usually do — but it's annoying.

I personally am a STR manager and know two STR managers in AZ (websites below) and happy to answer question about the process or what to look for in a good manager if you'd like!

-Most lenders have an appraisal appeal process.- See if another lender can use a lower qualifying DSCR ratio and 80LTV is possible on a cash out refi.

I know that searching for financing sooner than that is appealing, but the best rates that I have seen all require closing after 90 days of ownership.I will usually kick things off around day 60 of ownership and plan to close within four weeks of that. 

After all the planning it’s going to be 13 units total,One 4plex and three 3plexes

So he does not plan on moving out anymore and will stay until the remainder of his lease.

If you're planning to hold this rental for long time replacement is your best course of action.

There are key questions you'll need to ask about the group, the process, and of course verify their response with students.  

Yeah I plan on having a property manager in the next 4yrs but for now I can manage most things myself.