Agents overseas??

Yep, it's fine. Almost everything is done via email and phone calls these days, so having an agent in the US or UK is completely realistic.

My agent's in the US, and I'm in Australia and we work together well

I'm not 100% sure on that -- book hasn't sold yet, my agent's still pitching to editors

I'd assume, though, that I'd travel (if I fancied it. My understanding is that you don't HAVE to travel, unless your publisher's going crazy about you being at BEA or something) because we're targeting the American market with my books.

But there are plenty of Aussie writers with US representation -- Steph Bowe for instance -- who don't travel out of Aus. So don't worry about it too much.

The conference/event folks might pay your expenses or you might have to do it. It varies. I've had both. If they really want you there they'd be more willing to pay your way to get there.

Either way, your agent won't ever pay to send you anywhere. That's not their job. You publisher is the one who'd pay for events IF they decided to send you on them. They don't always, and it's usually just with the "big" books and authors who they know will draw a huge crowd and sell lots of books. But every author and book deal is different, so you'd have to ask them.

Trips to conferences are tax deductible for writers