'ap' is given by Chambers as an abbreviation for 'apparently' (and 'apparent'), so it's legit, although I'm surprised to see it in a DM crossword, where one expects a rather less 'rich' (ie obscure!) abbreviation palette to be used.
'1' and 'I' are treated as interchangeable in puzzles ('I' being the equivalent Roman numeral to the Arabic '1'), but I cannot justify the replacement of '°C' with 'C'.