Combat Mechanic Ideas

I have a few ideas for possible mechanics.

Overwhelming degen (ie, over -10) should reduce heal efficiency on that player for the duration of the degen. I don't know where I'd put the breakpoints, but I think it would have a vital effect on the game, possibly breaking the dominance of heal party over degen.

Increased Casting would allow the addition of casting time to a spell. This already exists with migraine and daze, but there are more possibilities. Enchantments and glyphs could add casting time in exchange for a second effect, like reducing energy cost or doing damage. Instants could be cast as a punitive measure like an interrupt, slowing the casting of an enemy spell by adding either a certain amount of time based on the interrupt, or a percentage of the original cast time.

"Stunned" would be a new condition, and it lengthens knockdowns on stunned foes for an additional second, to a maximum of 4 (3?)

It could only be used effectively by PvE enemies (don't ask why), and would waste a valuable skill slot in PvP for the same effect as Stonefist Gauntlets.

The difference being that Stoneskin gauntlets can only be on a warrior, this would stack with them (up to 4 seconds), and would apply to anyone causing a knockdown on the stunned character.

But I'm more interested in discussion of the other two ideas, particularly degen in excess of -10 having an effect on healing efficiency.