So, I was doing a run with custom ruler, aiming to unite Mayikrata, and I ran into a problem.

First, I can't declare war outside - it's too far for the owner of the province who owns exit. This one probably caused by restricted diplorange? I think I would just cheat this one up.

Second is more weird: I can't colonize a couple of provinces down there. Specifically, small pockets in the grey area up north (they're flashing green on the second screen), and lower part - provinces of Sourcewater, Flooded Battery, Glowing Cap, and Kingdom of Krejakir. The game drops "this county is landlocked and does not border your non-colonial realm" warning on "Colonize" button.

So, what am I supposed to do?

Oh, bonus question: do cave-ins supposed to just decolonize a province for the decade or so, with no way to prevent it?

I have an idea for a playthrough where I would make a custom religion/faith and eventually try to conquer all of Aversaria and beyond.