Mikael's Crucible and Bard ult

Its a Stasis so currently there is no way to affect its duration or remove it once applied. You can however prevent it by using ability's that prevent it from applying like say Morgs E or Olafs R.

I think bards ultimate makes them untargetable, so i dont think so.

highly doubt it cus you can't target them

There is a practice tool, go test it.