Mistakes I’ve made

@zavato 
You seem like a generous caring person.  However, your lending practices seem unwise.  When you lend, relationships can easily suffer when you try to get your stuff back.  Those folks who abused/dumped your lent stuff may now have guilt in their relationship with you and you may have resentment towards them.  Instead of helping them, you may be enabling their bad behavior especially the non caring irresponsible people.

If you must lend, make it very clear up front on when you expect to get it returned, let them know that you don’t like lending because it can damage relationships, then get them to agree to “can I trust you to return it on time?” maybe sealed with a handshake while looking them eye to eye.  Periodically tactfully reminding them of the due date may also be a good idea like 2 weeks before it’s due.  Also, you can say “did you used it yet? I hope so because I was really trying to help you out” - increased gratitude can farther increase their motivation to return your stuff.

Well, one relative I loaned stuff to is dead, and another relative I loaned to I refuse to have anything to do with anymore for other reasons

That’s a start 

I clicked a link to ASR thread once, insane.

Imho, it sounds like your friends confused loaned with gifted.  Since this has happened on multiple occasions with different people, perhaps you should make your intentions more clear.  

I cannot imagine throwing a borrowed turntable in the trash.
But then, I've never loaned (or borrowed) HiFi gear.
On the other hand, if you've never made expensive mistakes in this hobby, then probably you're either very young, very lucky, or you're not trying hard enough.

Some of my biggest mistakes involved buying mid-priced compromise gear. I haven't fallen for too many expensive snake oil gimmicks, though. I did once buy a $500 set of isolation footers for my speakers, which did nothing much but make them wobbly. That was easy enough to fix by sending them back.

What's the opposite of expensive mistakes? Moving your speakers (or listening chair) a few inches.