Wizards have Blink to perform the majority of functions of the enderpearl. It's got limitations meant to prevent people from getting through 1x1 holes and other things they couldn't normally fit through. I personally think it's a bit counterintuitive to create a teleportation skill limited to prevent Wizards from getting through 1x1 holes, but then still allowing them to kill a couple Endermen and basically have an uber-Blink that bypasses those limitations. To my knowledge, the only requirements for using an Enderpearl on this server are that you're a Wizard and have one in your inventory. There's no mana usage, cooldown, warmup, level requirement, or anything like that that I am aware of.
I think that if you're going to limit Blink (which does have mana usage, level requirement, and cooldown) to be unable to get through 1x1 holes, you should at least make Enderpearl use require mana usage, a certain level, a cooldown, and the like. It just doesn't make sense that you'd have to level to get Blink and be bound by the 1x1 hole rule as well as those other things, while before even getting that far, you could just kill an Enderman and effectively do the same thing with much lesser limitations.
I think I'm getting a little tangled in my wording, and I'm probably not making my point as well as I could be. Basically, if Enderpearl use can bypass that 1x1 restriction that Blink has, it should at least have a level requirement and cooldown.
But, if you aren't going to limit it that far, then why limit it at all...? Already, you have to be a Wizard to use it... though that's just about the only restriction. It's class specific, yet it's not considered a skill. I can't really think of a less vulgar way to phrase this at the moment, but at this point, the restriction on Enderpearl use is pretty... half-ass. IMO, either call it a skill and treat it like one, or just leave it vanilla.
Again, I think I didn't word that as well as I possibly could have, but if you can actually understand it, that's my opinion on the matter. Chances are that it won't change anyone else's, but I'll put it down anyway.