when I rotate a single bone in the engine, will it move the vertices according to their weights?
Sure, that's what bones are there for.
I use them in combination with regular bones animation and bone rotate and move via code in my game, too. Recently I've discovered bone animation via shader for me which speeds things up a lot and opens up many possibilities for me (because the shader animation works for code-animated models and bones, too).
EDIT: Just create a test model by yourself before you spend money on stuff that may or may not work at all.