everyone's opinions will differ on this topic... well, okay, almost everyone's. anyway, here's mine:
if you rob or steal from me on larki, and try to use the agreement as a safe-haven on TA, and just pass the time by stealing nails, digging, etc... i will send you home (if i can). if you go to TA to fight, i'll more than likely leave you alone, and get you later (this is more likely if i know and/or respect the evil person than if i don't... and also note that many people here disagree and will send you home regardless of whether you're fighting or not).
if you steal from me on TA, you can probably guess i'll get you whenever i feel like it, whether you're fighting or not ;)
anyway, just realize that there isn't one hard, fast rule (and we wouldn't expect there to be, seeing how it's unwritten). be aware that people play differently. choose how you want to play. and hopefully it'll be a way that makes more friends than enemies.
--jason