The basement (with 10' walls) is in place and was poured with foam-insulated forms to it has massive R-value.

Its also worth mentioning that the tub has a piece of insulating foam approx. 9x36 down the underside touching the floor.Here are my 2 questions:1) Do I level the floor which would create a step into the bathroom? 

He showed me how to do drywalls and insulation and electrical and plumbing , flooring.

Insulate, new heating and separate water meters.

I would change them out. 6 windows are not that expensive in the overall scheme, especially if all the comps are newer builds with double pane, insulated windows.

As others said, the best insulation against recession is cash.

In 1946, lead pipe should not have been used;drum traps;unvented fixtures;cast-iron sewer main which is near, or at, end-of-life.General:Asbestos - in flooring (9x9 tiles); drywall mud; pipe wrap; external siding;rock board / plaster board - drywall was still a relatively "new" thing and some of the early iterations were hard boards intended to replace lath as a substrate for plaster;barker board - common in kitchens and bathrooms;gypsum wool insulation  - paper-backed insulation batts spun from molten rock and slag.  

We are replacing the gypsum board and using a fairly expensive system to replace the moisture barrier and insulation.  

Maybe injection foam insulation is the answer but what if I do that and it doesn’t work?

If you get into building new construction or need any insulation for your fix and flips, let us know as my dad started his own business in insulation.