I did the online course (real estate U) because I have a young kid but it was super dry and boring, though it got the job done quickly and cheaply.  

This is the time to have dry powder anyway, and I see this all as the same bucket, since it's all cash and cash is fungible.

Was this a dry cleaner before.  

Keep some powder dry to take advantage of deals when the market turns and to double down on the sponsors that perform on your initial investments.

It sounds like maybe some confusion here.The one test mentioned is talking about the main water lines holding pressure all the way up.You use a ball check valve and when it passes the plumber is supposed to remove the valve and put in the regular pipe piece and then the dry wall workers go over it.The sewer test is different than the water line test.I am not a plumbing expert but is seems the two are getting mixed up.If you get the inspection you absolutely can go back to the bank on the short sale and show what is found and ask for a reduction.Show retail rates for labor and material and add 10% contingency to that.

When renting out a storefront, look for a business that requires the customer to come in (restaurant, hair/nail salon, massage, etc.).

So, its still going to be the same dry material.

When the l/o failed (partly) because the sprinkler system twice flooded my full, finished basement @$1800 in carpet and pad, drying it myself each time. 

I hope I don’t pull my hair out too much!!!!

If the plaster is pulling away from the lath (horse hair and glue eventually fails), you may  be able to use drywall screws and buttons (washes) to pull it back in-place.