My close friend in Florida has big buildings and he fills up all the pools with cement to prevent from liability. 

I'm wondering if some kind of stone/cement would look okay, and that wouldn't look too weird compared to the neighboring properties.Just one example:https://images.search.yahoo.com/images/view;_ylt=A...

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!

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."

And painting the garage door white, gives you a nice clean left-to-right consistency across the house.I was thinking it would look nice to paint the red cement porch area black, and the window trim black, too.The black blob over the garage door is supposed to be a large black really cool light fixture. 

This summer I will power wash and paint the foundation cement out front as it’s chipping away.