Pale: Yep, you can still talk to the animals. You can also send letters to them once you've met them

Also, you DO have the power to boot out jerks. Trading would be done by dropping/picking up items, so a quick bandit could potentially steal it, but I don't think that'll happen

I don't think you can sell anything to other people though....however, there is a Flea Market Day where you can put prices on the items in your house and have people buy them, but I'm not sure if you can do that over the Connection. I'm leaning towards "yes."
I was in CraigIGN's town just now and I tried to trap him in a circle of holes while he was out, but he came back before I was done. Circle-trapping could be deadly to people without shovels'
"Hey, can I borrow your shovel, I promise to give it back!"
"Okay, sure ju- wait, wah, oh no stop!"
With two other guys on your side, you could easily shovel-ambush the fourth guy before he can do anything about it!