i think the problem of tying tp to an item is that it makes it extremely hard to balance, i don't think that's the route riot is gonna take specially since they seem content with top laners using tp by default
as far as more macro summoners, that'd be nice, but i think it's gonna be difficult for riot to find another summoner that's as generally useful as tp, which is probably tp's problem in the first place.
but i honestly think the above is all you need to nerf it, just play with the cooldown until tping to countergank botlane is as punishing as it should be. i think the reduced cooldown on turrets should stay since it's something that makes laners like malphite more viable, tho maybe the numbers on that could be tweaked too
as far as more macro summoners, that'd be nice, but i think it's gonna be difficult for riot to find another summoner that's as generally useful as tp, which is probably tp's problem in the first place.
but i honestly think the above is all you need to nerf it, just play with the cooldown until tping to countergank botlane is as punishing as it should be. i think the reduced cooldown on turrets should stay since it's something that makes laners like malphite more viable, tho maybe the numbers on that could be tweaked too