The visual impact of taking a hit is a clear signal to you that time may be running out in your current battle. In this sense, hit points are really an average of your ability to survive encounters, not how much damage you can take. Also, a mage with 25 strength will only have 81 mana, compared to 100 mana for the mage that has 100 strength. Not at all. Strength is certainly not as important as it once was, but strength still gives damage bonuses, allows you to carry more items, and figures into the each of the derived stats.
Strength is still very important.
This is a good point to consider. If we give mages more stamina, they may be more able to escape situations. We are still looking to see how we can best make this a win-win for everyone. My mage will have to take 100 strength to have full mana. Almost all mages are already relegated to this anyway.