Spice, I feel your pain. I'm the chair of the lake committee in my neighborhood, and I've got a 100 acre lake to "manage". It is a delicate balance on the weeds with aesthetics vs habitat, we have elodea in our lake, and have put carp in to try to balance it. We seem to be doing ok with it now, we add carp some years, and not others.
We have 2000 homes in the neighborhood, so the vast majority are not on the lake, so we have to "show our value". We renovated a park on the lake, and put in a dock with picnic tables, and benches along the shoreline. This has been hugely popular, and has been great for the lake. The HOA board has came to us asking us to make the dock bigger, and what else we need money for. Also the cheap Kayaks you can get everywhere, are getting alot of use. You will see 10-15 out on a nice day. The one downside to the wonderful park, is that it brought in a lot of people from outside the neighborhood, and we have had to hire monitors to run off non-residents. We've also had to add the cost of replacement locks to the budget as people keep cutting the lock to the boat ramp.
We've got a group of fisherman that are involved, and willing to help with projects around the lake. We have been able to sink around 400 Christmas trees over the last 3-4 years. We have also started having monthly tournaments this spring, with the purpose to cull small bass. The winner is the one that catches the most bass under 16". I've created a FAQ type sheet explaining why we need to cull the small bass that I pass out at the tourneys. Catch and release is so ingrained it takes awhile to get that across.
Like others have said, a shock survey is a great starting point to let you know where you are, and will give you great insite. The biologist that did ours was great because he asked us what we saw from fishing and combined that with what they found. He has also been great to answer questions after the survey.
Having access to a private lake the size of these is awesome, the only problem is when you want to add forage etc, the numbers you have to add get big which means big $$. We added Threadfin shad last year, and the minimum to keep it from just being a buffet was $7000 worth, but they have made a noticable difference in the last year.
Good luck, and know that you are not alone dealing with HOA's and managing the lake.