Err many of your suggestion don't make sense. That DoTs (all dots, not just sorc's) don't stop caps is a gameplay decision, not a balance one. They will break stealth if not cleanse first tough.
But mostly, they want to avoid a sorc dotting people just for the sake of it, and paralizing a team. Because thats a hit too easy.
Affliction becoming the current CT as well. The two sec root on a spam CD? Seriously?
Same for the self heals. You are suggesting a bit total of 4% heal on tick crits.
Do the math, it means on single target, a potential of 12% for all 3 DoTs if star align, even more for assassin who shares your tree and can have a 100% uptime on Crushing Darkness, so lets suppose a 35% crit rate, thats roughly 10% on 6 seconds as well. Now if you also tab affliction....
Class needs some loving, sure. But if what you want is a FoTM fix, you just move the problem elsewhere. Annihilation marauders used to have 2% on bleed crit. That made a LOT of self-heals and got nerfed, I suppose to make up for the 1vs1 unmatched ability of it. You are suggesting taking madness way beyond that. As it currently roughly has the pre-nerf annihilation self-heal, with an easier application of them.
When DoT's became a major part of the damage we do, it does become a balance issue. I get a long single target mez in the madness tree, or have the games dumbest long term cast time on a single target mez. Both of which will break within 3 seconds of application, because all three specs use Affliction.
I thought I put it in there, but maybe I didn't explicitly state it. Affliction needs to be on a 15 second CD with that change.
The self healing on DoT's WAS excessive on maras. Sorcs already have a self instant heal, plus can't pair the self heals with any defensive CD's. Right now the parasitism and devour combo isn't even noticable.
Kind of hard to have 100% uptime on crushing darkness too. Was kind of my first clue that you don't play sorc.
The only big balance change in madness really would be shock, a six second CD, being able to do 5k ish damage when Crushing darkness is up, I wasn't sure if 25% each would be too much and only 20% each would be better.