What I do with weights anymore, I do at home with dumbells. HOWEVER....I swim as it's "no-impact" vs. "lo-impact". My pet peeve is that same as most yours.
1. Don't do GROSS shit in the pool. I don't want to swim through your lugie so don't hack it out in the pool
2. Standing there chit-chatting when I need a lane
3. Floaty people on the floaty side of the pool. We have lap lanes for lap swimmers. Lap lanes arent your personal space where you can bob around on a noodle.
4. Slow people in the fast lanes when sharing. And, not stopping to let fast people pass if you do swim different speeds.
When there is no one else in the pool and someone asks to share a lane. Wtf