Use the the newest version 1.4 with the plugins which come with it as they are the best they are Jabo's Direct3d7 1.40 plugin Jabos Direct Sound 1.40 and N-rages Direct input 8 you should'nt have any probs unless your roms are bad dumps
I guess he meant rom revisions... and I don't know... later revisions have stuff fixed imo but sometimes work worse in emus... just try which works best...
ya generally go for the highest versions. but, older version may have worthwhile things (red Ganon blood in OoT for example). usually i dont find any differences.
The diffrent releases usually don't contain anything new or fixed as you can see, so my advice is to get the first one you can get over. It doesn't really matter.