As for regions...
If there's a movie or something I want to watch but it has different region than my dvd-drive on my pc or I want to back-up something, then I just dvd decrypter/dvdfab to copy it to hard drive and remove regions/protections and dvd decrypter/dvdshrink to copy it back on disc(depends on which ones work best)...I do NOT recommend Nero for burning an iso-image, just a note...
Thought of mentioning this, as if this was done prior to putting it up on torrent, it would save a lot of hassle for everyone else...
I'm not an expert of this issue however, this is just something I've learned by trial-and-error...
Generally though I prefer good encoded rips to actual images, because of the size and the fact that done well, there's not much difference to the original one...
Edit; With that said, I'm not much of a friend of .avi, and hardsubs in general. Softsubs, mostly with containers like .ogm, .mkv, have a lot less impact on the visual quality. Though I understand that .avi is a very 'easy' solution, as it can be played with virtually anything...
Sincerely, Blanchimont