also in response to stamina affecting your abilities, by increasting it to increase your ability to avoid the damage. Acutally not really as much as you are suggesting, because well, to block you use stamina, however i plan to play a dragonknight, with all the extra block reduction mechanics. So my blocking will be reduced alot and I wont be burning as much stamina to pull that off. However, the dodge mechanic will eat up alot of stamina, and it is not as cost effective as blocking will be. That being said, yes I could add in more stamina instead of health as I level, but with a reduction to the cost of block, I shouldn't have to worry about that extra stat when i spend attribute points. Also you can get extra stamina pretty easily on gear as well. Its alot harder to get alot of extra health to be an effective tank, so it is best to stack the health with your attribute points allocation, and spend your skill points wisely to reduce the cost of stamina usage on abilities.
If i recall correctly though, to get out of stuns, you have to use 50% of your stamina, that is a straight 50% no matter how much stamina you get. I also recall that dodge uses a straight 30% of your stamina to use, which again is straight %, not amount. Both of these abilities in all honestly are not stamina cost effective for mitigation and damage avoidance, so it doesn't matter if you stack extra stamina or not, they will burn the same percentage if you have 1200 stamina, or 1500 stamina, or 300 stamina.
As for the damage bonus when you max it out, that is new information. However, still not something to worry about in tanking, but their seems to be trade offs when deciding. I guess it makes sense, because if you do go max stamina or max magicka, you will need to be doing extra damage to make up for the lack of health.