Lotro's ui isn't based on LUA like wow's (Lua is coming, but it's still in beta and atm not very extensive). Lotro's ui elements are clumsier in many ways. You can move most of the stuff around and lock them around (
http://www.lotrointerface.com/forums...97&postcount=2)
These elements doesn't include the chat windows however. It can't be locked on it's place and you can accidently move it during game-play. My only advice is that you locate it somewhere where it doesn't easily get on your way where you go click-spree.