Spending the remaining money dedicated for a Masjid to build another Masjid

A: As for the second and fourth questions, the remaining money specified for building the Masjid should be kept for the same Masjid to be used for what it might need. Regarding the third question, there is no harm in this for the sake of the public interest which you stated in the question. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.