wow I finally reach the end of this (except for the video bugs which will be one day... !).
For the neocd screenshots : not convinced, it would have to scan the directories before you select them for that to be any useful, so it would slow things down with some input/output. Then when you are in the directory it's too late, you are seconds away of seeing the real thing in action... !
For compressing isos : there are actually 2 ways, you can gzip the iso, but it's quite unefficient. The best way is to extract the files from it and put them in a zip, it will be better compressed than simply ziping the iso and super fast. At this point you can just get rid of the cue file, just point raine to the zip you just made, it should guess about the audio tracks when needed (assuming of course their track number is in their name !).