[coldtea]

>Ever try redesigning a Wordpress site?

Yes, me and tons of others people over the years.

>* All those plugins are just a Big Ball of Mud, and trying to figure out how to apply a design to it, without breaking everything is kind of impossible. Change a theme? Lose settings, styles, major layout choices, menu locations. I can go on.*

Depends on how you wrote the theme (or which theme you've bought) and what you want to change. Like on any other platform. It could also be a totally seamless experience. If your whole IA was based on the way the theme did things (custom post types, meta boxes and so on), then you need to port that too.