What is the ruling on engaged couples engaging in all the aforementioned acts, and are they considered spouses Islamically based on their statements: "You are my wife before Allah, and Allah is our witness," and "I have accepted this marriage," and does this entail the necessity of divorce and 'iddah after ending the engagement?

The suitor is a stranger to his fiancée until the legitimate marriage contract is concluded. What was mentioned between them is not a contract, but rather a mockery and play. What they did of forbidden acts is considered a 'zina' (fornication) of the limbs, necessitating repentance and refraining from those forbidden acts, such as seclusion (khalwa), touching, and softening of speech. They must regret what they committed, seek forgiveness, and increase in righteous deeds. The engagement is merely a promise of marriage and does not permit anything forbidden. The legitimate marriage contract has its pillars and conditions, and what happened between them is not considered a contract, nor does the fiancée become a wife to the suitor through it.