I'm not sure if anyone returned to Vault 34 after clearing a few of the enemies but that's basically what I'm planning on doing. I ventured into the vault at level 10-15 and soon ran out of Stimpacks and RadAways. Regardless, I've also encountered a locked door which I couldn't get past. So, running out of options and time, I backtracked. I've killed every enemy up until that point though. Thanks in advance!

Yes, they respawn.It happened to me, I explored whole vault at one time and much later I had to return to vault to recover some auto-doc for Caesar - ghouls were back.

Thank you very much. Now, I'll come prepared and the ghouls better be too.