Hello,
Thanks for your feedback!
I know about most bugs and i'm planning to fix them, it might take a week or so to get a stable version, pathfinding in particular needs to be better as it causes all issues you stated with miners & knights not attacking, I will try to fix the MMR bug as soon as possible, MMR and leaderboard where implemented at the last point and doesn't seem to work well.
I've experienced losing a part of my castle too while developing but have yet to track down that bug, I hope I can fix it soon.
Adding some extra hitpoints to dirt and wood blocks is easy and will be implemented soon.
I'm glad you had some fun with it and will try to fix most bugs soon, some might be tricky to find :)