mine gets warm when I do things that use lots of data (streaming radio) or graphics (snes emulator). If it gets really hot doing normal stuff (browsing or checking email) - I'd keep an eye on it, otherwise...yes - a mini computer...one that gets hot when you push it.
as far as app killers? I uninstalled based on rec's here (see the linked thread), and my droid is more stable for it. my .02