If anything Sprint should not deplete TP being a universal action. This way melee can stay mobile and keep up with targets that have no use for their TP (casters). Give it a longer cooldown should this happen, but outright removal should never be seen as an option.

There will never be "intelligent" interrupts in a game with netcode as loose as this. When I used Kick on my Rogue I had confidence that it would interrupt a spellcast. When I use low delay abilities like Fast Blade or Fracture I can never be sure it will interrupt a cast, even when the bar is at 50%~. That kind of uncertainty just kills everything this system has going for it.