How do ravage health potions differ from high value versions damage health potions? In other words, if I have a ravage health potion that does 25 points of damage, and a damage health potion that does 45 points of damage, which is stronger? And if it's the damage health potion what, if anything, is the point of a ravage health potion?

And, I realize that this should be asked in the DG forums, but I don't feel like starting another topic and don't want to spam the forums: what the heck does the "Soul Tear" shout do? Or does it just not work? I never see any undead rising or anyone taking damage from it.

Damage Health and Ravage Health are the same thing, only Ravage is immediate and Damage can be over time. So, you have to know the duration to know the total effect. Now, if the game does not show the duration, then the Damage Health will just take some amount of time for the full effect that is shown.

Soul Tear does a good chunk of damage and, if Soul Tear kills them and you have an empty soul gem in your inventory, it will soul trap them and reanimate them for 60 seconds. You need to use all three words for it to work.

No, that's Drain Health not Damage health. Drain health does something like 15 points of damage every second for 10 seconds. Damage health does immediate damage.