Bump for visibility.
Personal thoughts:
If nothing else his passive MUST CHANGE. Last Gasp has given every frame in the game a better version of his passive. What his passive has become now is a death sentence in steel path. I don't care if it's removed or changed to just allow him to eat an enemy instantly, then limit it to 3 per mission (see for example Wukong passive).
I would simplify some of the mechanics. Mainly increase the starting cost of 1, and lower the base range + duration of the 3 and 4. They seem a little high when compared to most frames. I like the idea of a taunting tank frame as we've seen in other MMO's, since it would allow more damage based frames to exist in steel path without dying all the time. Though I would give him an Achille's heel like not being able to self heal with the abilities. Taunting should be plenty to fill that role. And healing 1.5x cost when abilities cost health just creates an infinite energy source. I foresee casting all his AOE's at the same time and out-healing Trinity and Wisp. Not to mention taking fatal damage from teammates. The new meta would become run Inaros> taunt> hide in operator> team wins. We all have our dream of our favorite frames becoming Swiss Army Knives of the game, but I feel synergy between different frames and operators is still important, and we don't need another wukong situation.
There's a strong argument for him to have gating in some sense. It's now been seen that certain eximus units can down Inaros in one hit, not allowing the "OH NO" moment of a shield breaking to make a decision on how to survive.
You are certainly passionate about this rework and have given it a lot of thought. So fingers crossed for something to come of this thread.