You know, I did all the skills for my OW class, and had no issues with any of them (except I choked myself the first time I had to flood and clear my mask). But a couple of months later, I realized I wasn't comfortable with a regulator out of my mouth, and I didn't like that about me. So, like the OP, I practiced switching regulators, and doing air-sharing drills, until I got so comfortable with a reg out of my mouth that I've come close to trying to BREATHE that way. I applaud Laurie for addressing her weaknesses, even though I do think that all that kind of stuff should have been addressed and solved long before a diver gets to a DM class. What was going on with her AOW and Rescue instructors, that they never asked her to do these things, or picked up on the fact that she wasn't comfortable doing them?
Anyway, kudos to you, Laurie, for fixing the problems.