Stuff like that is what various completion options are for. Ideally you only type crap like that out once, and for that typing with your left pinky on shift is sufficient for me.

Funny enough, I just installed a vim plugin that gives a mapping for converting variables between camelCase, snake_case, MixedCase, and UPPER_CASE. The plugin is vim-abolish by Tim Pope.

(This isn't really relevant to your post, just funny)

I use smart case autocompletion for this. Ctrl is just so useful, there are only a few reasons to use capslock (imo) and they're just not worth it.

    inoremap <C-x>c <esc>bgUWea

Type the identifier in lower case, and then <C-x>c(or whatever you feel like mapping it to).