Considering that a high RoF is still king in most conflicts, the current non-sniper semi-auto weapons are outpaced by even the burst fire ones, and movement is incredibly important to staying alive in any FPS, the NC would quickly be dominated in any and all situations.
That said, it's a cool idea if they could balance it properly. Unfortunately, semi-auto weapons usually look good on paper but still pale in comparison to their fully automatic brethren. The only reasons in BL2 to use a high damage, semi-automatic or 'as fast as you click' weapon is because 1) Ammo conservation and 2) it's friggin awesome. Neither of those are concerns when you can rearm yourself instantly at a terminal or ammo pack, or when friggin awesome still isn't awesome enough to keep you from getting gibbed by a guy with a faster weapon than yours. Borderlands is specifically designed towards allowing variant playstyles, mostly because it's not a competitive game - It's an NPC grinder. Planetside 2 would have to undergo major rebalancing, especially in terms of damage, twitching, and accuracy, to make the factions' weapons significantly unique from each other. I'm happy as it is, but would love to see some more of what you suggested worked into the game without being over or under balanced.
Until then, I think they should work on just making localized conflicts more balanced. The other day I was part of an NC offensive on a TR controlled tower, and there were easily 200 people involved. The teams were mostly even, with the NC having more armor and air and the TR having control of the entirety of the tower and probably a few more people. We had two of the flags in our control around the base, with one the scene of a constantly shifting front line that was the focus of the combat. The TR even managed to capture the point a few times, and at others was barely pushed thanks to some quick revives under enemy fire by an incredibly handsome and brave medic*.
It was great seeing coordination and teamwork on both sides, and it was brought about mostly because the teams were balanced in some fashion or another. I don't relish the dev team's task in encouraging such fights without breaking the game, but it's definitely doable.
*I may or may not have been said medic.