I've done a fair few pickups, particularly AV runs and they're not so bad. As long as a few people know what they're doing, particularly the tank, then you should at least get a win out of it. Speed runs however are doubtful without a good bit of practice.

From what I've seen on Ragnarok, linkshells will often supplement their runs with a couple of pickups if they don't have 8 available. As long as they don't screw up massively all the time they'll get invited again. I used this to gain a lot of experience and am now leading my own runs.