Most of the issues people complained about were game balancing. We'd see a whole new list of "(insert class here) needs to be nerfed" threads after each change to the game. First it was creature handlers, then it was combat medics, then it was pistoleers with full defense tree manipulation crossed with smuggler.
The attempts to fix those issues simply resulted in a new "cant be killed" type of build, which would be the object of the PVPers moaning for the next few weeks. The only people not bawling about the flavor of the month were those who were playing the flavor of the month.
As far as crafting - the highest percentage thing that made people mad on that issue was the fact that the company allowed one toon per account. If they spent points on crafting they would be weaker in combat. This caused alot of the powergamers to have 2 accounts, but the casual gamers who just wanted to craft had a hard time mining resources because they couldnt survive on the planets where the good resources were long enough to drop extractors or pick them up. Someone with a artisan - armorer - weaponsmith template being repeatedly killed by rancor and force witches on dantooine was commonplace due to no defense. If thats where the 900+ resource of the week was located, sucked to be them.
As far as musicians and dancers? People would put on a macro based template, and go to bed - only to wake up halfway to completion of their template. They would then crank out another macro before they left for work and leave the game running. When they got home from work they could level to master in their new template they werent even in the room for when leveling in its entirety.