Guild Wars 2

So i have enough character slots to have one character of each profession.

I started playing engineer and elementalist.
but after going into their profession forums,
I see nothing but people saying how useless the classes are.

I want to play a class that is not going to be useless,or passed by for groups because said class is hyped to be under powered or not good enough.

since i have bought extra character slots, I have the option of having one of each profession as stated before.

what roles do i want to fill? I want to be able to solo, while also being able to do things in groups when needed.

i do not want to be the weakest link.

right now my guardian is going along with this build
http://www.noxxic.com/gw2/guardian/support/pve/core-build-and-traits

I was wondering if there was such a build to where i could sustain more damage without trouble.

don’t get me wrong, this build is pretty good.
I was just wondering what other type of damage soaking builds are out there?
and what stats would i want on my armor and weapons? power and vitality?

so what kind of stats am i going to be wanting on armor for engineers?

also am i better off dual wielding pistols? or a single rifle?
so far i love dual pistols, not sure how viable rifle is though.

I have a low level engineer, I plan on getting to 80.
so my question is this.

how are engineers endgame?
are they still really squishy?
are they any good farming karma and gold?