Get Webroot and call it quits. I have tried all of the above and have found that it idles to high even in a non-rooted phone. I stripped the guts of my phone and only have DroidWall, Webroot, Memory Task Cleaner and Wireless Tether and averageing 120-148MB of memory usage.
With the other antivirus and malware protection, it ranked to 152-167MB.