I think regions have to be touching your realm to take them over. That's why I was a bit worried with the concept of taking over Chesland and Chesney, because I assumed we'd need Gretchew first. Don't count me on that, though. And as for D'Hara, I believe sea connections count as touching. Don't count me on that either.
Any realm that has a region with a coastline can TO any other region that has a coastline. On testing islands, that is.
Indeed. Vashgew has coast and Chesland has coast so it wouldn't be any different than taking over a piece of land across the ocean or something. And once we had Chesland we could take Chesney.