There are a couple good utilities out there that will let you play around with your GeForce4 settings. One of them is Riva Tuner. Also, get MadOnion's benchmarking utility to see the effects of tweaking your board.
I wouldn't worry too much about framerate with the setup you have, as you are more than likely matching your monitor's refresh rate (if you have vsync enabled) throughout your entire time on AH.
People have had different experiences with AA and AF. Try each out and see how it looks to you. Obviously, the more features you turn on, the more work the card has to do, and the fewer frames per second it is able to render.
I don't think I've ever been below 60 fps, even in giant furballs with smoke and clouds. Most of the time I'm pegged at 85 (only because I have it set to match my monitor's refresh rate).