I don't think teaching a soft bite really helps in this context. I teach a soft bite to my puppies, but that's so that they can mouth me, when they're playing. It's not about using their teeth to snap at me when they're unhappy about something.
The instances you're mentioning sound easily preventable though. Don't bother her when she's sleeping for one. "Let sleeping dogs lie." And when you want to teach her to wear a harness (or whatever) introduce them to her in a different manner instead of just ramming them on her.