and most of the time is  bad management, bought the wrong price, Interest and Insurance to the roof and, I cant get out the Bridge loan to do a DSCR loan etc ...Simple hands on, work do research and minimize risk. 

Outside of real estate I am in the construction industry, in Commercial / Residential Roofing.

Rent paid for all of the expenses, so it cost me nothing and over the years (I kept it for ~20 years) price almost tripled by the time I sold it.Not sure what grad program is 3 years (I'm used to 2 for masters, 4 for PhD), but if you do need to sell one, I'd look at each property and see which one has the most equity, highest interest rates, lowest return, major expenses in the near future (eg new roof) and you mentioned you'd lived in two for 2 of the last 5 years, so have capital gains exemptions. 

5) Why was new roof NEEDED?

That’s perhaps a B area.Do you see 6 inch tall grass, moldy siding, and damaged roofs here and there?

But your own psychology and mindset does matter, and investing in real estate, while not making us wealthy, did give us this back-up plan where we knew we'd always have a roof over our heads and enough of a financial buffer we could figure something else out.

It is regional, but I find some of the newer homes where I am have more open living areas, but the bedrooms are smaller as are some of the lot sizes.To get a new mortgage, your rates are likely going to go up, but if the new home was well built, you shouldn't have to worry about things like new windows or a new roof for a while.

It's the same case for hiring a highly referred plumber who will fix the leak and a few other things for the right price, or take the new guy no one has ever heard from and your leak has now turned into an explosion. 

But if you use multiple emails as I do for my businesses each Gmail account will have its own google docs space, I found it hard to manage all under one roof.

Also crawlspace air also not that good quality if air leaks through those loose ducts.