New main objective: Give gold to Ves
Everyone makes mistakes. If you accidentally robbed or hurt a Guild member, you won't get away unpunished. If you commit a more serious crime, like killing one of the thieves at The Ragged Flagon, be ready for everyone there to jump at you, bloodthirsty.
Keep in mind that you're not able to kill all the Guild members. Brynjolf, Vex, Tonilia, Mercer Frey and Delvin Mallory are immortal, so defeating them isn't possible. Also, attacking the thieves doesn't have any sense whatsoever - you won't again anything and just deprive yourself of teachers.
If you happened to commit a crime, you will have to pay in gold. Escape from The Ragged Flagon and wait three days. Afterwards you will be able to return to the Guild, but don't expect a warm welcome. You will regain the thieves' trust after paying a fine - 100 gold which you should give to Vex. Afterwards you will be able to continue completing the Guild quests.