2) The images in LR always show the last dev settings applied. To show the original you can do reset. IF you don;t want to loose the settings save a preset, or apply them to a vertual copy or do a Dev snapshot (above History in Develop.
4) The onlt back-up that LR provides is for it's dB (database) where all the metadata of nondestructive editing including keywords, crop, develop, etc) are stored. Anyother back-up of images etc, is up to ypu, as you should, as I said, be already doing that.
Don
Don Ricklin, MacBook 1.83Ghz Duo 2 Core running 10.4.9 & Win XP, Pentax *ist D
http://donricklin.blogspot.com/