Dear literary agent

If I could ask a literary agent some questions, here’s where I’d start.

If I’m a published author, how does that actually help me with any other publisher since most have “no unsolicited submissions” as policy?
What do you do? Research publishers? Network at writing conferences? Help flesh out marketing sections of proposals? Editing help?
Aren’t writing conferences kinda a good ol’ boy system?
Do literary agents only work with traditional publishing houses?

Any additional questions you’d like to add? Sigh. Not that I have an agent.