You can do that, but be warned that some users may find it unexpected and thus awkward; I feel that WASD is very much standard these days. If the spacebar is a serious problem, then I suggest finding a replacement key for that, instead.
Hmm… Here’s a thought: what about using WASD to control movement, the mouse to control the camera, and the mouse-buttons to control spinning and “Twirl Diving”?
Or, if camera-changes are fairly rare, and not required mid-action, perhaps put them on the arrow-keys, movement on WASD, and some other pair of buttons on the right-hand side of the keyboard for your two actions?
Indeed, I think that it’s generally a good idea to offer rebindable keys!
By the way, if you want a GUI-based key-binding UI, I’ve made available for public use my KeyMapper module. Note that it is very much “use at your own risk”!