Far as TP feed goes, I'd just be happy with a trait where, upon landing a crit, the mob has its TP reduced by some amount. This could be subject to resists, some mobs could even be immune to it, but the ideal effect should be that the RDM technically doesn't exist when it comes to the mob's TP growth, but they're still otherwise offering their damage. It's basically a subtle blow variant in that regard.
Even building on Enspells, continuous Enstone strikes could up Slow potency, Fire for Addle, and so on. It's not something completely without precedent if you look at COR's Quickdraw.
I'm still partial to my old idea of Enspells building toward a point pool we can invest in either offensive (stronger debuffs and nukes) or defensive (more potent buffs [See: Indirect Haste II] that last longer) boosts.