If I were a renter, I'd want to know if the locks had been changed or rekeyed prior to moving in.I would ask the property manager how they handle pests, rodents and bed bugs just to see if they replied with stories of recent experiences. 

It sounds as though the entire value of the 2nd office building is in the fact that you have a tenant lined up....so locking them into a lease would be the primary constraint.That being said, why don't they lease from the office building you already own...

It always does change and (b.) the amount of debt we carry as a nation will need to be paid and the likely place to get the money is the huge amount of money in 401(k)s and IRA's that is "locked in".

I’m just not sure if there’s room for profit after repair even if I were to lock it down for only 4K. 

Start doing the research now to find someone great.If you can reasonably BRRRR this property use the capital here so you can lock down the deal and get it moving.

We are submitting a bunch if offers right now to lock in a second project before the months out.

It certainly  always is advisable to exercise basic safety precautions, such as keep windows locked up at night  and when you leave the house, getting dead-bolts installed and using them, etc.  

And the squatter had done this multiple times.A former boss explained to me, that locks are to keep honest people, honest.

A good lock-box, perhaps with internet connectivity / a slick app to check on who is coming in/out.  

If you can install yourself, I've used floorstoyourhome.com and got click-lock vinyl plank as low at 1.22/sq ft including shipping on sale.