After more than a week away from it, I've made some progress on my rigging script - it now rigs Daisy's clavicles, and attaches her arms! More importantly, I've split the Daisy-specific commands off into their own script, so now the core script can be used on other characters!
There's still a bit of work to do on the core script before it's ready, though. Here's my to-do list so far -
Once the core rig is finished, I can either get back to adjusting Daisy's skin weights, or test the rig on a Warcraft character or something. At some point I'll also need to figure out how I'm going to rig Daisy's face, and how to script that rig so that it can also be applied to other characters. Then of course there's her breast rig... there's no way I'm not calling its script "boob job". :P