Alternatively, the direct console commands are:
set skycaptainssb.bashkey to XXX (bash key to key code, can remap to a mouse button via this method as well)
set skycaptainssb.flipkey to XXX (flip/evade key, can remap to a mouse button as well using this method)
There's a list of the scancodes (XXX) that you can use http://cs.elderscrolls.com/constwiki/index.php/GetKeyPress. I personally map them to buttons 3 and 4 of my mouse.