that way I save $ and he makes some $ simultaneously. 

It's not just a theory, I put it into practice for over fifteen years, and it never failed.

Is this a common practice or should I run like crazy.

What's the best practice when looking at a rehab or shell?.

Have them run it for at least a couple years and then if you decide to take management in house you can follow their best practices.

I practice commercial only but occasionally handle portfolio SFR sales.

I can refer you to my investing group's financial experts (accounting firm / law practice), if you like.Where the issue may be getting confused is that the interest on financing is an operating expense for income property, but the principal portion is booked under debt service, as I understand it.

Should I consult with various lawyers and a CPA, is it better to go with a firm that has experienced in various practices such as corporate and tax law and maybe immigration?

It is now fully occupied all with leases of five years or more, one being my own practice and three other medical practices.  

There are best practices to ensure that subject-to's don't result in a lender calling the mortgage.