do you ever take time to go to a pool or maybe 20ft deep open water area and just practice dropping your weights and handling the quick decisions required to keep the situation safe?
No. It's dangerous to practice what could easily become an uncontrolled ascent. Also, I'll add that if you dropped an actual lead blocks weight belt in a pool, you'd probably get a different kind of injury pretty soon.
Exhaling into my BCD and re-using the air on the way up.
This seems like something experienced divers could know about, but way too much task loading for OW divers.
I cannot do this [photo of diver underwater sitting astride a cylinder]
That's because you're doing it wrong. Turn around, then reach back with the butt end of your knife and knock the valve clean off. Ride it up.
Who defines what "overly thick" is?
In ancient days, a 1/2" farmer John with a 1/2" beavertail, with gloves and a hoodie, seemed just right. But there is the issue of compressibility being a factor that could cause surprises at depth. I wasn't taught that wet suits could actually make it hard to ascend in some circumstances.
I remember one time I left a 12-14 lb weightbelt on a ledge at around 80 feet in a Florida spring while wearing a 7 mm full suit. I dumped all the air from my BC and just swam around with zero air in the BC - it was a nice feeling without the heavy belt and the BC puffed up.
I wouldn't expect someone to be able to retrieve a weight belt promptly, so I'd assume it had been there for awhile, and that the owner might not be coming back later. Even so, I'l leave it, but I do think that a lot of people believe that gear on the bottom is affectively abandoned (I don't expect to ever again see the 3 pounds I had in my jack-o-lantern to keep the pumpkin neutral this past weekend, which fell out at as I was swimming back). Thoughts?