Disclaimer: I don't have this game, I might be getting it later today (possibly not) so I have very little idea how this game works.
Skip to TL;DR if easier.
I'm potentially getting this game later and I wanted to ask about class balance and how desirable certain classes are/aren't. After a bit of scouting I decided I wanted to roll an Inquisitor but from reading around, apparently these are played quite a lot.
I read instead that Agents are underplayed and was wondering if this would increase my chances of getting into a group at all, or if being an Inquisitor would lower my chances. I play a Hunter on WoW and for PvE it's often pretty hard to get into a PUG as a Hunters seem pretty popular.
Would picking a popular class limit my chances of getting into a group?
Would picking a less popular class increase my chances of getting into a group?
What is the role most people want atm, Tank, Healer or DPS?
Tanks and Healers will always be in demand. Perhaps even more so, as we do not have dual specs and respec costs can get pretty crazy.
As far as DPS balance goes, it's far too early to know what does the best DPS and what doesn't, especially since we don't have access to the combat log. For all we know every class does mostly the same levels of DPS if played correctly. That said, I do see a lot of 'LFM non-Jedi DPS', but I think that's just because the pug group former is getting sick of all the Jedi players, not because they're bad or anything.
Honestly, the only correct answer here is this: just play what you enjoy. Don't pick something that you dislike just because it's underplayed, or overpowered, or whatever. If you're a good player then you'll find groups regardless of class and role. You'll also have more fun if you're playing a class you actually like!
At the moment I don't think it would matter too much, Operatives will be welcomed because they can heal and do decent DPS and Snipers are (from what I can tell) never turned down as they have some serious firepower when allowed to wail on an enemy.
At the moment there aren't really "popular" classes and specs because everyone's still kind of feeling out what they enjoy and what synergizes with other classes. And as for specs I couldn't tell you the difference between an Engineering Sniper or a Marksman Sniper yet. There's no real utility difference between the 2 and there are no damage meters to tell you which is better. All in all I'd go with what feels like the most fun for you at the moment and work your way into groups.
As for what's most wanted at the moment I would say probably Healers but that might just be my server.
Right now, class doesn't really matter so much as the role that you fill. A lot of the classes can either be DPS/heals, etc based upon the AC that you pick. Inquisitors do seem, to me at least, to be the most popular class on the Emp side. I have no hard data on that, it is just based upon what I have seen as a Rep player.
My best advice would be to find a guild that suits your needs, and apply to the guild based upon the merits of you prior history. Fill whatever role they need by selecting a class that can fill that role, regardless of what the class actually is.
I'm a level 31 marauder(Dps) and I find very difficult to find groups. As usual tanks and healers are hard to come by.
From my experience, it really does not matter what Dps class you play currently. With out tons of people playing endgame heroic flashpoint / ops, its hard to say which Dps class is good or bad, or even which might need pve buffs / nerfs at this point.
Also, I can tell you that any melee class in pvp is incredibly frustrating. Huttball, specifically, makes me want to break things. Every other class can sit on the high ground and shoot or cast on me. If I try to go up there I'm pretty much knocked around like a pinball from everyones AOE knock backs. If I try to battle in the open, I'm literally swarmed by the other team in 2 seconds flat.