Don't know about the Sprint greeting, too small of an issue for me to care I guess.
Advanced Task Killer is great - there is also a widget that will kill all of your apps. If you open up the app, and "click and hold" on any app, you can Add an Exclusion the ~6 important apps that shouldn't be killed, Android Live Wallpapers, HTC Checkin Serv ice, and Advanced Task Manager itself (although you can let it kill itself, that is fine too unless you use the Auto-Kill feature).
Even when I don't use the Advanced Task Killer, and with Live wallpapers, my battery life is fine.
The only things that I have found to really destroy my battery are (1) playing games and (2) installing crappy apps that do shit in the background (I have yet to find a crappy app that I don't want to disable, so if you are picky and want a million apps running that's your problem). If you open up Advanced Task Killer you can see all of the open apps (and even though Android claims its memory mgmt is okay), you should kill unimportant ones anyway. Any apps that need to be running in the background will startup automatically again after that.
You should really just kill all of the unnecessary apps at Startup, since almost everything is open at startup. That's what I do, I don't kill apps except for (1) Startup and (2) Before I play Asphalt 5, since its so resource intensive
