Some of these changes to the rules were similar to things I was thinking of. Part of the changes I was considering toying with had to do with making the Balkan countries a bit more feisty. A lot of that would involve giving Russia an initially stronger setup in some places (though with no bump in artillery) and making Bulgaria a playable country in its own right (i.e. think about how China works in A&A Pacific). Serbia would give Russia a couple perks, but Romania would be a sad sack. It would make the Balkan area of the board a whole lot more interesting.
I like your Kiel Canal idea; I was thinking of the exact same thing. To that I might add a mine roll of 1 or 2 when attacking German units in the North Sea off of Germany. This would represent the very heavy mining and the defenses of Helgoland. And that plays right into a major part of the German naval strategy for the High Seas Fleet: run away!
Along with this would be Britian’s battleship off of India going to the North Sea and being replaced by a cruiser off the coast of India. I would have to find out exactly what they had off of India in 1914, but nothing that would be represented by a BB in the game. About the only dreadnought worthy of the name east of Suez was HMAS Australia, not counting Japanese units operating with the Royal Navy on convoy and patrol duties.