1) No. No. Nonononononono. If this were removed, then what would happen if people kept leaving in World of Darkness after not getting (or getting) their loot? That alone is enough of a reason to keep join in progress - and why are you waiting half an hour before asking your FC for help?

2) Would you rather get grouped with a premade then booted out literally within the first 5 seconds because they don't like you, your gear, or whatever? Besides, 5 minutes isn't really that long anyway.