Amazon App Store a CPU/battery hog
One thing that recently increased my battery life was uninstalling Amazon App Store. I had downloaded a lot of free apps of the day and other apps, and apparently, no matter what your notification settings are, AAS will keep pinging your phone for update status (and possibly other reasons, like seeing if you "need" new apps). It shows up as both a running app and as part of the Android OS percentage. Watchdog Lite keeps citing it for CPU spikes.
Haven't had a problem with downloaded apps not working yet, but I'm told it's likely.
I'm betting that Google play app update pings also strain the battery, but I'm willing to live with that. Probably a good idea to uninstall apps you'll never use again, though.