In English we can say:
Well/So, it's time for me to leave.
So/Well, what can I do to help you?
Well/So, what's the problem?
Is allora an equivalent of "so/well" in these cases?
In the first example I'd use "Beh/be', è ora che io vada". For the other sentences "Allora" is fine, but you may also use "Dunque" which however is a bit more rude.
You may use "bene":
Well/So, it's time for me to leave -> "bene, è ora che me ne vada"
I think that it depends on affirmative-negative or interrogative forms. If you are asking something you can use "Allora dove andiamo?". If you are in the affirmative form you can use "dunque". The expression "Beh" usually is used only when you are speaking and not in written form. Another way to translate this form is "Ehm"; that indicates that you are trying to take time and don't know how to answer: "Ehm, non so se uscirò".
It has come the time for something (sudden decision): "bene, beh"
Bene/Beh, io vado (it's time for me to leave).
You want to push someone to do something or you're annoyed by something: "allora"
Allora, andiamo? (shall we go?)
Allora, hai finito? (have you finished?).
You want to push someone to take a decision:
Bene/beh/allora/dunque, che si fa? (what should we do now?)
You are asking something to someone: "bene/allora"
Bene/allora, cosa posso fare per lei?
You are asking something to someone as a consequence of something said before: "bene/allora/dunque"
Bene/allora/dunque, hai preso una decisione?