That's one reason I want to wait to be higher level before opening my shop. With the trader PrC, I'll be able to open a shop. With it, I'll be able to do 2 things, first, a little profits, second, I have some idea of adventure that could happen, and it would be Rinaldo who is the employer (Yeah, that mage ask me for the elements for a magical item, but I miss one. I don't have time to fetch it myself, would you? Or, a thief stole half my stock, if you find it, I'll give you that nice magical item. What do you think of it?)
Guilds and guildhalls exist, even if we're not roleplaying what happens in them. It's happening all the same. In between returning from the adventure on which you (i.e. your character) gained a level and checking into the Red Dragon Inn in the hope of finding a new adventure, suppose you spent a little time in an appropriate guild hall doing whatever was appropriate. You can talk about that if you went, maybe share some stories over a bitter at the Dragon with your next adventuring buddies. But if you want to play it out -- that means other real-world people need to be available to play all the NPCs you meet, and I don't think the LEW project is nearly large enough to justify that.
Similar comments apply to shops -- if your character is going to buy some gear, you'll add the items to this character sheet, subtract from the gold listed, and suppose that that's done. There's no need to actually have someone playing a shopkeeper. A lot of what happens during downtime is too boring to bother playing out in any detail. But it's happening all the same.