Lumping together the Jewish wedding blessings with the breaking of the glass at the end of the ceremony is roughly analogous to lumping together the Catholic nuptial blessing near the end of the Catholic nuptial liturgy with the presentation of flowers to the Virgin Mary. In other words, you are lumping together an integral part of a nuptial liturgy with a more or less optional pious custom.
The groom is certainly being extremely generous in agreeing to marry in a Catholic nuptial liturgy and agreeing to allow children to be raised Catholic. Insofar as it is possible to please him and his family by importing Jewish customs into the Catholic nuptial liturgy, every effort should be made. But the Catholic nuptial liturgy cannot be subverted by including rituals that might not be entirely consistent with the Catholic faith. (I don’t know the Jewish nuptial blessings well, so I cannot say one way or the other whether they are appropriate for a Catholic nuptial liturgy.) The breaking of the glass, on the other hand, is a pious custom and the Church generally is quite lenient about allowing pious customs to be included in wedding ceremonies.
Bottom line: With the permission of their wedding celebrant, the bride and groom can include the breaking of the glass at the end of the marriage ceremony. But if they want the Jewish nuptial blessings read, that should be done at the wedding reception.
