Flipper paints it grey, puts in clean cabinets new fake flooring what can go wrong? 

If the septic is covered by a slab of concrete, how will they ever clean it out? 

If that's the case, you can't do any renovations until you have it professionally deleaded or it would be flagged for Unautohrized Deleading and you can get fined and the property would never be able to get a Lead Certificate, only a letter of Environmental Protection that states you did illegal work, got caught, then had to pay a professional to clean up the mess.

I have a 750 credit score with a clean record.

We honestly felt bad that she had paid”professionals” to clean carpets and do a move out/in cleaning.  

Spend whatever it takes to get the correct respirator, prepare thoroughly, and clean up thoroughly(bought a new a shop vac just for this, with the special drywall dust bag and also a HEPA filter).

One other negative, and I don't know if this is true for all because I only have one, it is designed to hook up to a hose bib for cleaning.

The countertops went from drab and beat up to bright, clean, and new-looking.  

How deep is that experience?

We cleaned it and mowed the lawn, and that was about it.