With Ul'dah, it seems to me that the refugees are treated in much the same way as the real world homeless. I mean, you guys even make it sound the same. "Why don't they go join a guild?" "Why not just go get a job?" The refugees probably got refused by the guild the minute they entered, wearing pretty much rags and no skill to show for it. So sure, it would be nice if someone went and taught them a skill or two so that they can go and join a guild, but in a city like Ul'dah who would do that?
And as for picking up a sword and joining up to be a gladiator in order to eat...That's like telling a homeless person that if they're hungry, they should go and try to join the military. Go put yourself in harm's way and hope that you get accepted and fed.
We as adventurers do this because that is what we are. We throw ourselves into the fray and relish in the life of danger and adventure. That's not the life that every average citizen is capable of.

Lastly, and I promise this is the last, sure, those people who are in the guilds may be ONLY goldsmiths, or ONLY armorers, but they have dedicated years to their craft and I'm sure that they can craft things that are way beyond us. I mean, we have to go to Serendipity to get a mammet made. Why? I'm a lvl 50 gsm couldn't I have made it? Nope, because for all intents and purposes, I may be a really good goldsmith, but I probably only know the lite version of the craft. The real thing requires dedication and years of practice and honing the craft.