There's also a suggestion at the "thinking out loud" level: in Jebus Cross, make it possible to optionally disable terrain penalties (except sand) - this would greatly balance things. Cove, Tower, and Swamp (although to a lesser extent) are weak largely due to the penalty. Similarly - on XL maps, allow all towns to build level 5 mage guilds.
And yes, I think Lizard is right, even if he put it a bit bluntly. I have nothing against casual players who have never played online, but it is the online community (not just ХВ) that is the driving force behind the game's development. Without online play, there would be no Heroes in its modern form.