If the disruption is great, consider housing the tenants temporarily at a hotel while the work is underway.Expect this to require permits from your municipality/county.

Now that I’m closing in on 1500 units there are some issues that would cause me to switch to a higher end solution if it wasn’t so disruptive. 

Do not be disruptive as many are more skilled and often they are selling you something.....

Yes, you have to work around tenants need, and I understand them wanting a legit offer with proof of funds before disrupting tenants, but make sure you have a cancel fee in your offer, and refuse to go through if you can’t see it. 

The industry is overdue for disruption....

That said I was wondering what experienced wholesalers  do  or would do to dot all their i's and cross all their t's on the property to ensure there aren't a bunch of liens or other issues that would disrupt a smooth closing before calling a title company and spending hundreds of dollars for them to do the same thing?

It's tough to do a complete upgrade to an occupied unit so in this case you do the easier stuff like plumbing & lighting fixtures and appliances, window blinds, countertop resurfacing, pretty much everything but flooring and paint which can be too disruptive. 

Your conducting business everytime you sign your name on anything......It all started with Wikipedia....Schools are fighting the internet disrupting their market share on education.

(Hence the comment above.)Remodeling is disruptive and dirty, not just in the room being worked on.

In this way I will limit calls to disrupt my day and can simply check my e-mail and call one of a few handyman I've spoken with.