Small things like caulk, grout, screws, thin-set are the responsibility of the contractor.

I didn't approve that but since they can do it electronically (my mistake giving that ) I'm screwed ,I don't think I can send them 3 day notice if rent is partially paid? 

The former landlord is basically screwed in seeking recourse, and of course the new owner can get nothing from the tenants either.

And are there any major concerns I should concider so I don't screw myself over?

And are there any major concerns I should concider so I don't screw myself over?

Well, here comes Hurricane IRMA and screws up one of the target MFs necessitating a new roof which the seller refuses to negotiate on.

We are all trying to screw the other person out of something. 2) SF and MF are completely different.

(You may want to talk to a local lawyer to ensure you are complying with local laws on this)This will have three effects, 1) it screws your unethical property owner  2) It protects your monies which you might get to keep after the foreclosure and 3) gives you leverage with the bank that is foreclosing.  

Tenant pays everythingAppraised Value: $40,000 (Appraiser screwed me by using foreclosures as comps.  

Remember you have a mortgage to pay too so dont let them screw up your investment with lag of financial discipline.