Not complete, but a start ...
Archididascali Admodum Diligentisan utterly scrupulous/diligent Headmaster
Haud Infidelis
Vico est Functus
Quoad Privatam VitamNever unfaithful, as attentive in town/village matters as in his private life
Vidua TristisHis sorrowful widow ...
Then the abbreviations
H. M. S. P. S. F. refer to what she did. It probably begins
Hoc Monumentum, and probably means something like ‘had this monument placed in his sacred memory’, but the exact wording still needs more work, sorry.
Quć Multa Curavit Satis
Nec Ullum Opus Neglexitwho amply took care of many things and did not neglect any duty
P. Kal. Mar.pridie = the day before 1 March, so 28 February
Lubens Decessitwillingly departed/died
(agreeing with Spidermonkey above

)
ADDED
Uxoris Fuit Amantissimus = he was
most loving of his wife