Does a divorce occur with the statement, "If anyone other than a mahram touches you, you are divorced," if the fiancée shakes hands with her non-mahram employer or is kissed on the hand by a young man with whom she had a previous relationship?

If the Shari'ah contract has been concluded, then the divorced wife with whom consummation has occurred is subject to the conditional divorce if the condition is met. A divorce before consummation results in a minor irrevocability (baynunah sughra), and the divorced woman cannot be taken back except with a new contract.

However, if it was merely an engagement and the contract was not concluded, then this is a conditional divorce before marriage.

It should be known that assumptions based on delusions have no weight, as the default state of a Muslim is soundness until proven otherwise.