just today after the tantrum she had before going to school it felt like she didn't deserve it (probably we were too angry).
The things that occur to me here, is it's so early in the morning for tantrums - even in my dc's tantrumiest phases, they usually started off the day in OK moods - unless they were ill. Is she definitely getting enough sleep (about 11.5hrs for average 4yo)? Not coming down with a cold/cough?
Otherwise, if you're already quickly angered, at the beginning of the day too, it sounds like a bit of a rut that you all may have fallen into. What happened in the lead up to the tantrum? A specific incident?
Not sure I agree with the smiley/sad faces being equated with 'good' and 'bad' behaviour. Are they also 'learning', that it's only acceptable to be 'happy', and it's not OK to be 'sad'? However, as the school use it, I see why you might want to carry on the consistency at home.
I agree that you should stop making the book at bedtime, only depending on the smileys earned. It should be a foundation, part of the routine regardless - because the benefits of having quiet time with her parents, learning to read while having a snuggle, far outweigh the 'message' of denying it because she missed getting enough smileys.
It's great that you tell her when you see she does something you like, and why - keep doing that!
With the choices, I don't give my 4yo that many - limited choice at her age works best, not a whole vista of overwhelming decisions. So, it's A, B or (at a push) C. Not the whole alphabet! For instance, stuff like: "You can wear this skirt, or those trousers. Which do you prefer?", NOT [throws open wardrobe] "What would you like to wear today?" Then if she doesn't answer, or says "I don't know", tell her that you don't want her to be late for school, so if she doesn't choose by the time you've counted to five...you will have to make the decision for her.
Or, you can even circumvent all that by sorting it out ready the night before - no faffing around in the morning if she only has one set laid out ready.
With the getting dressed - "Great, now let's see if you can get yourself dressed like, a big girl!" Set another time limit - "by the time the big hand on your clock moves to [x]" Or maybe something she can relate to "by the time it takes me to get myself dressed"
Make sure you praise her to the skies as soon as she meets any of your requests, because it all builds up into a feeling of independance, and increased confidence, and wanting to do things to please you because they like it.