Casting time for healing spells?
 

By how much is the casting time reduced for every skill in life magic you have? Is spell healing pretty much inferior in every way to skill healing now?

It's not at all. The lowest the timer gets is 2 seconds, and that's with 10 life. That life raises the amount you heal, with major healing you heal 80-110ish, in 2 seconds. Pretty sure that's faster than skill healing. It's only effective if you have the skill points for it, or are a paladin.