Ok 1st things 1st: I'll run E/W myself if I want to. Nobody's going to tell me to change.
I'll address the comments one at a time:
1st; Tain: The scatter of sandstorm can be addressed by having a dedicated snarer in the party. Failing that, a MM will clean up any leftovers nicely.
2nd: ArKain: You mean you didn't stop reading when you saw "E/W"? Thats usually enough to put most people off. Having said that, hamstring was just an afterthought really - the meat of the build is the aegis warders - the 1st unit is all me and skills I might run. I'd normally keep wild blow in there for the record. Hamstring isnt exactly an AOE snare after all.
3rd: Puebert: Firestorm is better than it used to be, true, but it's still adjacent only - a tiny range. Overlapping sandstorms can potentially cover a massive area of effect, 3 firestorms could cover a pinhead if you're lucky. As for being W/E. Well, this is a build I run with my near 2 year old ele, so I can't exactly change her primary profession now, can I? But yes, a W/E as the aggro grabber might work better. Then again, a W/E will have energy problems if they try to run the exact same skillbar as me.
4th: beltran: Ebon Hawk+Stoning=KD on ONE foe. Typically that foe will be the healer in an enemy mob, so they are less likely to be attacking anyway. otherwise, Ebon Hawk wont get used unless it's to catch strays
5th: Epinephrine: ...
6th: Kazjun: SF will be ready until fire attunement gets stripped. Then you're in real trouble. Although yes, this commands that a stop start strategy be used, even if earth attunement gets stripped, it wont be enough to completely shut either the offense or defence down. Ok, so SF has all the virtues that you've mentioned, it does burning, which can be combined with 'Theyre On Fire!' (A great skill which was in the authors opinion, overnerfed because of it's popularity,) and the damage output is better than sandstorm.
However it's also boring and monotonous, just like the whole fire attribute, (I'm not saying fire is bad, far from it, it's just I find earth far more interesting.) Earth has the advantage of being far more balanced - you couldn't effectively run a warder that uses fire for offense with out compromising on the absolute power of one or the other. Dual element builds are few and far between, not because people are lacking the imagination to make them, but simply because they're generally so horribly inefficient and ineffective that they're simply not worth it.
So yes, you could run a fire elementalist, but it wouldn't be worth giving them any defence to speak of, meaning you would have to concentrate more into the remaining 4 slots of the party. The way this build stands, you just need 2 monks and then the last 2 slots could be absolutely anything that enjoys killing stuff - a cripple D/x or A/D would gel perfectly with the SS warders.
A Curses necro, eh. Well in high end PvE, I'd say they would be better suited as the damage dealers of the group. It's long been argued that necros are the better damage dealers and I'm inclined to agree because of their armour ignoring skills. Hell, at the highest level, even smiting monks are going to outdamage eles, (Why do you think our Guild's fow team nuker is a smiter?)
Anyway, like I said before, it wasn't designed to be perfect or uber, or anything special at all, but I use a team build that is heavily based on that - ie my personal build is a bit different, doesn't have hamstring, has 2 sword attacks etc etc BUT, I use it and quite happily as someone who plays GW for a hardcore amount of time but in a casual way, (if that made any sense...) and I thought I'd share it with everyone. I'm glad I did, It was worth it for the Hamstorm reference

Now, if you'll excuse me, I'm supposed to be working atm...