As I work my way through the levels, I have thus far been picking stamina almost every time I level up, so that I can get the extra 5lbs carrying capacity. But does stamina do anything else for me? Does it have anything to do with how much damage I deal in combat?

Now that I've bought a house, I'm thinking I more or less wasted all those points and should have put them into health. I'm pretty much playing a strict stealth/assassin type, so I have very little use for magicka. For that type of character do you think it's more important to focus on health to live longer? Or is there more to the stamina rating than just being able to carry a bit more junk?

Stamina allows you to carry more weight and do more strenuous activity for longer. Not really a waste, depending on your build.

That green bar. Depletes when you sprint, and use "special" attacks (hold mouse button while attacking, shield bash, etc). More Stamina means you can do more of those attacks. They do a lot more damage than regular attacks, and can cause the enemy to stagger or pause, break their block if they have a shield etc, so as long as you utilize all that stamina, it's certainly not wasted. *I haven't played a thief, just read that bit, so don't know how it plays into that style. Imagine doing such an attack from stealth would be absolutely devastating though, getting the hidden multiplier on a power attack.

Any melee class should use Stamina as main stat, as you hit harder and can block longer.

It lets you sprint longer, zoom in longer with a bow, and perform more power attacks with weapons.

Hmm, I was wondering where the penalty was for using Eagle Eye... Did not know it used stamina. Thank you.