Technicly the following stories are mostly not groupfinder (from the time before there was gf).
I was doing the Hammerstation FP on SM. In our group was sentinel who acted very weird. Each time when the tank assigned a target to CC the sent started to attack that particuliairy target. He did the same when he marked something for CC himself. The whole fp went pretty decent nonetheless. When we arrived at the last boss the sent was performing very very poorly, standing in red circles, standing in the AoE blasterfire cone. The group decided to dump the sent and try to get a replacement in.
Once I saw a lv 50 sent (focusspecced) that was doing lousy damage. When I saw what attacks he did I noticed that he was wasting zealious leap, stacks of singularity were running out without him using forcesweep. All in all it was obvious that he didnt know his rotation well. To make it worse. He had loads of high endurence pieces because 'it gave him more HP to survive attacks'.
One time I was going into EC SM Z&T with a full guildrun. The raidleader actually requested a vanguard dps to attack from range. Truth be told, we only had 1 ranged with us. Suffice to say that we didnt made it (we were about 75% rakata-geared)
Very recently I went into the FP lv55 with the rocked dude at the end with 3 friends. The fp was doing pretty good but that wasnt surprising as we all knew each other and were well geared. At the last boss the 3 friends decided to pull a prank on me and not breaking my shackles. After 2-3 wipes or so I decided to stand in closerange with my GS so that would break my shackles by accident. In the end we finally downed it, with me still shackled and waiting about 45 seconds till my cc breaker was off cd so I could break my shackles :P
We went into EV HM for a gearing run. It was again a full guildrun. There was a commando dps participating that had issues with TS, so he went without TS. That part wasnt to bad IF he knew what to do. At the first boss, even though I clearly told him before hand to stack when we did stack, he refused to come. We even typed during the stackingphase to come and stack.
Sinse his gear was mixed with cunning, willpower tankinggear and other none commando dps gear his dps was terrible. It didnt helped either that he only used his hammershot (we assumed cause his ammo didnt dropped). Because of that we werent able to kill the boss so I swapped from my tank to dps.
At the infernal councel we decided to let the commando wait and do nothing, cause his dps wasnt great enough to kill his target. Even though we told him to stand there and do NOTHING, he ran around like a chicken with his head cut off, attacking every single councelmember he could.
One final weird thing, it was so though to actually gear the commando up. We tried to convince him that the pieces that dropped were better. No luck.
To conclude a nice sentinel story again.
During doing some dailies I teamed up with a sentinel who clearly didnt know what to do. One off the things was that he used inspiration off cd. Allthough you dont need it on trashmobs its not a bad thing either. Bad thing was that he always used it AFTER we killed mobs, sometimes even with valourious call
OWH and FYI, that sent and raidleader from 1st till 3rd story? That was me. It took me quite long to figure out how to play it. This is my first MMO and never have been raidleader. Now I know what to do and what not to do. I consider myself a relalitve skilled SWTOR gamer. As told by other people, we all start out as newbies making stupid mistakes.
Lets hope that the people targeted by this thread will turnout okey.
Little addendum to the 3rd story. The guild where I was in didnt have any ranged dps except me. Also it was our 2nd time we tried EC SM. After I noticed on Mox that the vanguarddps was doing even less dps then the tanks I quickly decided to let him close range again and take the fearfull.