Tout à trac and à brûle-pourpoint I would use with verbs implying some kind of verbal interaction such as dire or demander. I’m not sure décider and tout de go go well together. Décider de but en blanc is ok. But in your example, since we have 54 years of marriage and a sudden decision to divorce in the balance, I’d say :

• Mais papa, tu ne peux pas décider du jour au lendemain de divorcer de maman après 54 ans de mariage !

To sum up, it’s more a question of finding the right verb to go with each of the four expressions than a question of nuances of meaning between them.