Might and magic serie is my favorite rpg, this year I finished first part, I was having a lot of fun by creating maps.
Alex is expert on Ultima, maybe he can give valuable hints. Problem is with absolute mouse, but in some cases you can pretty good experience with relative mouse + enabled two point tap gesture. I finished this way mm6 and Albion. I can say, for these games it was better then with absolute mouse.
Your images shows perfectly:)