As far as exterior, either redo all the siding or just the pieces that need to be redone.

There are a lot of moving pieces when getting into Property Management, do not underestimate the amount of effort or work involved. 

Some brands are better than others for having the nose pieces for the front of the stairs.

There are already means to sell pieces of individual properties (simpler than options like condo conversions).  

To answer your questions: The seller financing piece is likely to complicate your refinance.

One piece of advice I want to share is get a copy of the tenant lease!

If I had a piece of advice other than being patient and not caught in fomo, it would be to really try to get to know whomever you do business with wherever you invest. 

How long will it take you to piece together the information you need to be successful?

My biggest piece of advice would be to take it slow and learn to evaluate different options and strategies and hear different opinions (you don't have to take them all and use them, see what works for you... there are a lot of them on these forums LOL) as soon as you can.

The odds of all the pieces doing their jobs flawlessly are long.