It can take some people some time to learn how to solo with a coercer, others pick it up right away, but no other class in the game really solo's as well as a coercer can if done right.
A troubader can do much of what we can solo, but it takes them a hell of a lot longer.
Charm is mainly useful soloing
Mez is rarely needed, but it can save a group or let them take down something they couldnt otherwise, really overusing this ability will slow your kills and your exp down
What a coercer mainly offers a group at your level is
Mana Regen, if you are pulling fast enough you will definately need this to kill downtime, if you aren't finding it useful, your group isn't killing fast enough
Stuns decrease damage and coercers are the masters of stuning, most mobs cant do anything while stunned, if you are lacking a healer this helps immensely, it also helps to just decrease the number of heals period and frees up the healer to do other things like debuffing or dpsing which will further decrease mob damage and increasing yours
DPS...you CAN dps, you are no assassin, but you do more damage then most classes
Debuff mental...this helps your tank to hold aggro, taunts are based off of mental
boost DPS..you have a dps buff, make sure to put this on your tank and melee dps, it may seem small and it is at first but it gets better
In general at your lvl and even at high lvl (you just get more stuff) in a group setup a coercer adds Power to the group, slows down mobs, adds dps, and has the ability to Crowd Control in the rare situations it is needed. It is a utility class and can be replaced with other utility classes just like healers can be replaced with healers and tanks can be replaced with tanks.
In soloing its easier to solo with a wizard or an illusionist, but neither can take down as powerful mobs as a coercer can, but it takes skill to do it with a coercer. You can solo heroic yellow names pretty easily once you learn how, and you don't really need a pet to do it, a pet when used right just speeds it up and makes it a tad bit safer.
With orange and red mobs....its not really worth fighting these for the most part while leveling. They are hard to kill, your spells and melee attacks dont land as often or as hard and it generally makes the xp suck, just wait a lvl or three and kill them then.