Flat panels will be a better option when compared to rear projection because: 1) Rear projection use a lamp (just like common projectors) that has to be replaced after some rated hours of TV viewing. Just check the specs but this could be between 200...
Since it is a rear projection, yes it can burn in if you leave it on hours on end. Check what is the highest resolution your TV can handle and do not exceed it (it won't break it, it will most likely just say NO SIGNAL or EXCEEDED RANGE...but better ...
Sounds like what you mean is a FRONT projection screen. The link below will show you how to make one yourself.