Drag drop file A to file B to rename A with B's name but keep A's original extension. Maybe optionally with a keyboard modifier.
With modifier Shift to do the same rename, but on a new copy of A, at the location of A.
With modifier Ctrl to do the same rename, but move, to the location of B.
Ctrl+Shift = rename new copy at the location of B
I do use F2 to rename and copy paste but most of the time I feel it's too many steps even so.