I only cleaned it out by ordering dumpsters and tossed out garbage and ceiling debris.

I'm also experimenting on a build right now and exposing the ceiling joists on the first level as well as the ductwork.

I had to dig down to meet ceiling height (among dozens of other things).

the way I read asbestos potential is that is has to be "friable" to be any danger. in other words say you have raw unpainted ceiling tiles that are falling apart, that asbestos could be considered to getting into the air.

You’ll need a general contractor and understand of building code since you are turning this from a residential 1-2 family building into a commercial 3 plus unit building- do you have 8’ headroom throughout the basement as an example, do you know to do fire and sound proofing ceiling assemblies for the new unit and common stairwell areas, do you have 1 hour fire rated doors in any common stairwell built into your budget, how many egress windows have you budgeted, what about plumbing, heating and electrical as they all have meet code requirements?  

We test for lead paint but are just careful with rehabbing asbestos infused drywall & popcorn ceilings. 

We because of the cleaning and lack of time to run our Ozone machine, the new guest complained they could smell smoke (which was likely the ceiling) and Evolve refunded their stay which we believe that that we should still be compensated for the guest stay and because it was their guest that smoked causing the refund to the new guest….3.

I take it all the way up to the ceiling.

Should things like the ceiling, flooring be checked right away?

I know it's not dangerous if it's not disturbed, but some houses already have walls, ceilings, floors, or insulation that have holes or need to be completeley replaced.