Learning English, any correction is very welcome.
ele for pugging
If you are going for full DPS, you could get some problems in PUGs. I’m currently using this build for pugging and I’m happy with it. It is not optimal for damage (though still all right), but I rather deal some damage than lie dead on the ground. I swap the utilities depending on the situation.
If I understand well, you ask, how hard it is to stay alive as ele in dungeons? Due to the versatility of the elementalist i’d say it’s not hard to stay alive, even as a full zerker glass cannon. If you learn the fight mechanics, you will know when to dodge or use evade skills, so surviving shouldn’t be an issue. The real art is dealing the possible highest damage, while staying alive.
Survivability is the lowest out of all classes, you have to sacrifice some damage slot skills (or traits) in order to avoid getting 2-shotted.
Unless of course you are very good, know exactly when to dodge, know fight mechanics, etc.
No issue.