OK then on those criteria I think it is important to make the distinction that there are consumer-level MPEG2 editing tools which can do a good job. Womble MPEG Video Wizard and Video Redo can both edit down to the single frame level and do not re-encode the whole file again; only the parts that are necessary. Even Ulead Movie Factory can offer single-frame edit resolution.

Nero and the like are not really designed as serious editing tools - really more for authoring - and indeed only offer editing resolution down to the GOP level (roughly every 15th frame).

Vegas and Premiere are excellent for uncompressed AV, but are complicated applications so probably not advisable for the beginner.

They're all good but have obvious limitations; and relative success just depends on the type of starting material, and level of skill of the user.