Nice guide!
A few things:
You can't extend the time for using the shield like you can with ducking.
I found that reacting a few steps before obstacles allowed you more time to respond to other obstacles that came right up after. For example, jumping a few steps before a Hoplite allowed you to immediately kill a farmer right after him. Or, dodging a tree a few steps before allowed you time to immediately block an arrow strike.
I don't know about anyone else, but I didn't get the medal for unlocking all the game modes - or do unlocking all the armor count for this?
Bobogoobo
It may be worth noting that sometimes when I jump over the large obstacle at the end of the level too early, the level will not end and I have to restart. So I always make sure I wait until the last moment before jumping.
DiMono
I haven't encountered that particular bug, so I can't confirm it, but you may want to get in touch with the game's creator to make sure he knows and can look in to it.