We can use the continuous form in the conditional clause to emphasise that the situation ishappening ´right here, right now´. (If they are coming with us, they nned to get ready)
If we want to emphasise that a situation is different from what it would otherwise be, we can use if it were not for.
(If it were not for her courage and determinatio, she would not be here today)
We sometimes use will, would and going to in the if clause in certain situations. (polite request, annoying behaviour, intention, refusal, cooperation)