I think EE is a vital part of Tekkit. While some items such as collectors are too OP, other items such as condensers and red matter stuff should not be banned. While yes EE makes resources easier to get, for those who have the time to spend gathering all the necessary resources without it, good for you. I on the other hand do not. I do not wish my Tekkit experience to be me, in a hole digging up copper to make some cables for a generator when I could just throw a piece in a condenser. For me it's about making machinery systems rather than making the machinery for said systems. I prefer the idea of a new player "trust" system rather than banning. With EE I have done nothing but create amazing(in my opinion) builds, not break down mountains with the click of a button. Plus IC2 has plenty of items to grief (i.e. mining laser and industrial tnt).
On the topic of starting a new world I do not believe it would be a good idea. As V00doo has pointed out before in about a month or so the problem would only be back, but now people would have lost all of their builds AND be playing with as much lag as they are now. I think a better option would be to just go through each players base and checking for lag sources/ helping people figure out a better method for their machinery. Another thing to consider would be going through the log-ins and seeing who has not been on for long periods of time, informing them of this, and if they still do not come on often remove their base/machinery.
For people that say the game is lagging, some methods to help combat this are:
1. Go into your optifine menu and turn all your settings to the lowest possible.
2. Turn your render distance to tiny.
3. If suddenly things get very laggy look up, especially when chatting with someone, as there is nothing to render in the sky things run smoother.
Once again EE should not be disabled as it is very critical to gameplay and the world should not be restarted.