Great details. Aeration might help clean some of the stuff up, but that's going to cost $$ (well, everything will!).

Your bass look healthy, despite being thin. (yes?) I'd guess that if the LMB are living in the water BG should do okay as well. These fish aren't young at that size, so clearly they've found the pond habitable but it looks like forage is jumpy. If the LMB reproduce - and my guess is that's been the forage - as Theo said the BG will find a way as well.

I think you have 2 generic strategies - starting over (elimination of fish), or managing your way out of it. Sounds like option 2 is where you're headed.

Regarding removing the LMB - you could do this, and probably should. If you look at this as a long-term plan the more LMB you take out now the better shot you have at getting a forage base built. It doesn't sound like you've got a huge crowded situation, but I can't imaging trying to build a forage base without culling LMB - they'll just eat everything. Your 12" fish might be 4-5 years old - and you don't want forage going into them - you want it going into new young bass.

It would be hard for me to remove the 22" fish, so you could either leave some or take them all. But you have a problem - the 22" fish can eat a 5" bluegill. So the more big fish you leave the harder to get your BG to a size to be your forage foundation.

The key to long-term sustainability is getting your forage built (without getting eaten!). You can try multiple species, like BG, RES, and Golden Shiners - but the key base of the bass foundation is the BG. Stocking enough adults (5-6"+ fish) to make the difference is the challenge.

Here's the rub: You could put a few thousand adult BG into a pond that size no problem.