The Roll : I like it.
The Quick Dodge Jump : um, maybe. Allow blocks during this but maybe not attacks.
The Dive/Lunge : I think this would be cool if it landed you in a very compromised position (as in you couldn't execute attacks or blocks for a second), so that this was a highly offensive move but a little dangerous to execute, a risk.
** For all of them, I would say their effectiveness (speed or execution, distance, etc) should be based off things like agility and weight, so that heavy plate strength buffs aren't agi rolling all over the place and leaping around as well as a high agi character in cloth.
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Overall, besides the roll I'm a little unsure, because one of the beautiful parts of MB combat is that its so SIMPLE in its basic controls....LMB, RMB, WASD, and yet the combinations between all these and the timings etc can separate a hopeless newb from a MASTER of armed combat. I dont want the game to lose this aspect.