G.B.
She's too old for the toddler bed now so I'd probably just skip it. They're for toddlers not pre-schoolers.
The clothes issue is manageable by what you put on her. She can have footy pj's on and a heavy duty safety pin through the zipper pull so it won't come down without being un-done by stronger hands.
The onsie's on backwards does work but with her size all she has to do is pull pretty hard and they'll come unsnapped.
I'd duct tape around her waist over the taps of the diaper if she's pulling the tabs open to get the diaper off, if she's just sliding it down then that won't work.
At 2 she can start potty training and sit there before bed time, it can't hurt her for sure. Offer her a reward for "producing"...lol. We did one jelly bean for pee and 2 jelly beans for pooh. My friend did the tiny M&M's. Another did Hershey Kisses.
It is an incentive to get them wanting to go. She'll do okay either way.