We bought ours February 2011. No porn, no root, no 3-rd party apps outside of market, no abuse. I was having these problems before and after I used any kind of task manager (downloaded from Market).
Many of the issues went away after upgrading to Gingerbread... but I did gain a problem with Gingerbread with the text messages randomly skipping to the top of a text thread while typing a text message. That never happened to me before with Froyo, but I had random text sending issues with Froyo that were just bizarre. I can guarantee you our problems had nothing to do with user error.