Actually having reread your op, I will share a bit more of what worked for us, in the vain hope it will help!
So bedtime goes: wee, teeth, PJs on, into bedroom. In her room she's allowed to pick 2 bedtime stories.
Before we start the first one, we say 'OK, we'll read two stories, then I'll stroke your back for a minute, then I'll go downstairs so you can fall asleep'. Read first story.
Before the second one: 'Ok, after this story I'll stroke your back for a minute then I'll leave you to fall asleep'
After second story, rub her back for (now) about 20 seconds then kiss goodnight and off we go. She'll chat to her toys and sing songs for a bit then fall asleep.
Once she's in bed for stories, she's not allowed to get out again - toilet breaks excepted.
But for us, one person had to do it, and stick to the script so that every night was the same until she knew what was coming.
We also do a version of rapid return, but involving conversation. So if she starts to talk to us, we say 'shh, it's bedtime now, time for talking is over, go to sleep', then 'shh, no talking, night night', then just 'shh' until the message sinks in.
Hope some of that helps. Sorry about the essay.