Also, there are so many times where the enemy is completely unflinched by my blows and proceeds to hit-trade me in tournaments, what gives?
The tournaments are not "Balanced" in that everyone has the same gear like in practice mode. Some what realistic. Gladiator battles they used the best equipment THEY had. Not a "Standard" equipment load out. Chances are if you hit someone and they keep swinging, they have high tier armor and your attack was too weak to hit the stutter threshold. Where as your peasant armor you eat a hit for 50 damage and get stunned.
As far as being hit when you "Know" you blocked. There are 2 options. Either you didn't fully block, and they grazed you. I've also noticed I get hit when blocking, but recordings and replays have show that the weapon hits both the shield AND character and does minor damage 10-20 ish. Instead of the full 50 ish for a Direct hit. So your shield caught some of the attack, but not all of it.
Or it is a hitbox bug, where the weapon hitbox goes through the shield and connected with whats on the other side.
In my tests so far, it seems that the first option is more likely, and that weapons can now "Hit around" shields. Which was that point of axes. You can "Block" part of the attack, but block it wrong and the curved axe head can still hit you. It's not just an automatic block if you catch some of the weapon. You now need to catch the entire attack.
The physics engine seems sophisticated enough for this, as with the 2H axes, if you hit with just the handle, and not the blade, you do basically no damage. So the reverse should also be true in the use of shields. If you block just the handle, but get hit with the blade, you will be damaged.