All the tenants are small-town mom-and-pop type business owners, insurance offices, lawyers, hairdressers, home health care, dentist, etc. 

I have seen people pull all the copper from the home and pour cement down all the drains because they were pissed off. 

It sounds like your situation is easy to remedy with vinyl cement patch and waterproofing paint.I am not sure courts would consider water in the basement a habitability issue.

A fellow agent here in NJ told me a story about how her client had a awful tenant and didn’t want to leave when he was evicted so when he was finally forced to leave he flushed bags of cement down every drain in the house!

It had been removed for some reason and put in the freezer...these are two dentists mind you...not crack heads...still thought it strange but had they not pointed out that it was in the freezer I would have had to figured out a way to fix it.

The other plus is it will cover us if my husband wants to do an excavation job or make a cement countertop for someone (his new passion). 

I'd let them walk and be happy about it...this is a tenant who will flush cement down the toilet!

Like, "I'm looking for a SFR or multi-family building with at least 4 bedrooms in zip code 12345 within 1.5 miles of the college campus, with simple roof lines, so if it needs a new roof, it won't be super expensive, preferably a rambler and not a multi-story, with a detached unit that could be converted to an ADU at some point, with off-street parking, preferably with gravel and not cement in bad condition that will need to be repaired."

The professional/commercial unit downstairs is a pair of dentists. 

No easy answer for this one, IMHO, this Corona will be contained quickly in USA... but with a 'global' economy freaking as it is, "you might feel a little pinch" the dentist says as the needle goes into your gum.Everyone:  hang in there, stay calm, be safe.