A hypothetical to see how people factor costs when rolling equity forward into additional purchases.For this example assume  you purchased property “A” for 100k, and put 25% down. 2 years later you sell it for 125k so you now have 50k (25k from your initial down payment + 25k in equity).

Call one of your architects to do the research for you, noone in BP will have all your answers, they are too specific, your architect and the building department will know the answer to those questions. your firm should be able to get quotes from builders mentioned on your profile.

I had to figure that out for myself all on my own.

One key differentiator is first time investor vs. first time homebuyer - it will be much easier to qualify as a first time borrower for an investment property loan if you own a primary or at least have done so recently

That being said, I want to waste no time in figuring out what the next best move would be, especially as someone who's interested in the buy-and-hold strategy and in managing my own properties (at least in the beginning). 

Each building has its own checking account.

Did it lead to more damage to the furniture/property and end up lowering your ROI?

Not furnishings but selecting the materials that will go into the new design of the home. 

That is something to ask your lender.

@Michael Magno Can you PM me with your rec too