RE: More GreasePencil Animation mixed with 3D overlay/rotoscoping
It absolutely is! Especially if you do it in 2d I think XD I've done both 2d and 3d and I find 3d easier _; or at least easier once you either get past the rigging (I hate rigging!) or can con get someone else to do it.
RE: More GreasePencil Animation mixed with 3D overlay/rotoscoping