I would not say VG burst is significantly stronger than sent, seeing as how a sweep bomb into a group of people is harder to heal through than just one person getting nuked. You're right that VGs are glass cannons, and guess what the best counter to a glass cannon is? Kill them first. That doesn't work with sents, and chain CCing them doesn't quite work if their team has good healers that know what cleanse is.
I agree with you the game shouldn't be balanced SOLELY around 1v1s, but it should be balanced around it partially. I'm fine with having a LoL type (rock, paper, scissor) balance for 1v1s, but currently it's rock, paper, scissor, HULKSMASH, where sent, vgs, shadows are the HULKSMASH that own everyone else. That's not ok.
In WoW (the only other MMO I've played seriously), every class had a good chance to beat most other classes, and get utterly owned by some (or at least manage to stalemate). And they still managed to balance the overall larger scale pvp quite well.
I'll give it to you on the aoe burst point, my error for forgeting that. However, I've never really worried about smash as an aoe, 3+ people standing beside each other for the smash is just plain stupid. I think most of us agree rage needs a minor nerf too.
I'd agree with partial balancing for 1v1s if that didn't detract from group pvp (which should trump all), I was getting a bit irritated at people insisting 1v1s were the sole determinant of a class and so generalised slightly. I don't really like the rock paper scissors system though, as long as there are counters to a class I see no need for classes specifically suited for defeating another. I prefer skill deciding the winner where possible (limited by the need for group balance, but that's as it should be).