Aranea - I'd ask myself 'does it really matter? What's important?'
Does it matter if she has a late bedtime? Yes, she gets tired - can she sleep in the next day to make up for it?
Clothes: What about letting her go to bed with nothing on? You could always slip some clothes on her when she's asleep, or give her extra blankets if you think she'll get cold.
Teeth: Brush her teeth while she watches something on tv? Would she respond to being timed to do something - set a buzzer and see if she can do it before it buzzes.
Loo: no idea! What about having a special book to read and sitting on the bed with it waiting for her - tell her you need to be downstairs in ten minutes, so she'll miss out on her story if she's not with you very quickly.
Can you start bedtime earlier?
Shouting and screaming very normal, especially at bedtime when everyone's tired. Take a deep breath and walk away when you feel really angry. An extra five minutes won't mean the end of the world. Tell her you're close to losing your temper and are going in another room and please can she finish on the loo while you're calming down. Expect her not to have finished so you don't lose your temper all over again!
Try not to take her dawdling personally - see it from her point of view. If you were tired, and sleepy, you'd probably be doing things in a bit of a daze. I know I sometimes feel too tired to get ready for bed and wish I could click my fingers and just be in bed in my pyjamas!
Ooh, just had another thought, my children have sometimes responded favourably to a soft toy puppet thing asking them to do things, or to help them to do things like hedgehog saying 'Oh DD1, can you help me clean my teeth please, and then I'll help you with yours if you like'.