Requiescat in Pace (let him/her rest in peace) is typical of a Catholic MI.
If the child was under age then a legal guardian would be needed - if the parents were dead (& I guess deported is equivalent) and there were no near relations on the Island then in the case of goods the General Sumner takes charge - to be honest I don't know what happens re children

Re marriage licence - 99.9% of Manx married by applying for a licence rather than using the banns read out in church - I'm not aware of any surviving records of such licences