Your healing rate really should not be fast enough to help during combat. If you take some damage and then go exploring or talk to some merchants, etc, your hit points may get topped off by the time you are done.
With a Survival value of 200 (much more than you could do in normal gameplay), you would have a Regeneration value of 100 (assuming no equipment bonuses, etc). When I checked this for the guide, I only saw 16 hit points recovered each minute. Even if I missed some other factor in hit point regeneration, during actual gameplay I never noticed significant healing over short time periods.
I'd like to know what kind of stats you had with your DK, but it sounds like you may have run into some kind of bug.
What difficulty level is your game at?
You can increase the difficulty level in the game menu, but if you raise it to hardcore it can not be lowered again.
In your new game, how did you do against the ghosts in the cells just before the arena?
The skeletons above ground in the BF are not particularly tough, that I recall (pretty much only used the BF for the merchants), but the ghosts should have at least been be challenging.
People have played high strength / low agility characters and vise versa, but I don't recall anyone reporting good success with low strength and agility. A high survival will help with elemental resistances and initiative (which can make a big difference in tough fights), but I would think a low agility would result in a lot of missed swings.
There are all kinds of ways to build viable characters in BD. I didn't do the math section for the strategy guide until after playing and establishing my characters. I adjusted stats as I went, and came up with something that worked for me (which I described a bit in Killing Fergus
). Other people did the same thing, but came up with significantly different builds, even of the same character types. That is one of the reasons the recommendations on stat point distribution are a little vague in the guide.
That said, I don't recall anyone else bringing up a significantly different healing rate between different character builds or games.