If she's Spirited, I'd bet a year's salary (if I got one LOL) that threats will only add to the tension. You might try talking to her out of the moment, like during the day, and just tell her that you need her help to stay in bed/her room once it's bedtime and you don't WANT to close the door but you don't know any other way to help her stay in her room. You might be surprised what she'd come up with - Josie often surprised me with ideas of her own, and/or once she understood the problem in a more intellectual out-of-the-moment step-back way, she complied more readily, when it wasn't a battle, a her-vs-us scenario.
We actually make bedtime CD's for our girls; in fact, they help us pick the music, and each girl has a CD player in her room with her CD's. DH likes to do this; he's the iTunes guy, loves to play with the different features on there, and they like snuggling with him in his lap and helping pick tunes.
It does sound like she's waking cranky. That was why we had to get Josie off naps, actually: when she napped, her bedtime ended up so late that she woke up already tired and the day never got any better, PLUS if she napped, the cycle would repeat day after day.

I did sometimes have some success getting her to at least lay down in bed for a while longer sometimes if I stayed with her, and once in a while she'd fall back asleep if it was dark enough, and/or if we put the sleepy tunes back on.
Is your DH at home in the morning when she's awake before he goes to work, or does he get home in time to give her a chunk of Daddy-time before supper? Mine has to leave early, but he USUALLY (and I use that term loosely, since we live in a horrible-traffic area

) gets home in time to play with the girls - but Josie usually wakes before he leaves so they at least get to touch base before he goes. Can you guys have a designated phone-call-to-Daddy time during the day?
BTW, we also have a rule here that after supper/6PM we wind things down. After supper is NOT wrestle-with-Daddy time, but before supper is fair game. (We suspend this rule on weekends or if there was a nap, like if we had a long drive and one or both slept in the car and they NEED to blow off steam.)
Any chance DH can try putting down DS? We generally try to alternate nights with the girls, although there are nights where one parent does both bedtimes now.
Just a few thoughts.
