Hello,
Welcome! I hope you can find what you need with Archicad.
Personally I've quit Revit for Archicad and I have no regrets!
So,
1) You can lock individual elements or layers. You can hide layers but not elements (but you can assign them to different phases where you won't see them).
2) You can't constrain elements in space like you can with Revit.
3) You can't constrain columns in a specific position or constrain elements to a given position. But you can do it through Grasshopper / Archicad connection.
4) You can find several tutorials in the youtube archicad channel.
Cheers,
Felipe Ribeiro Cunha
AC 26, macOS Monterey