Can the child of a Muslim, particularly a revert with a non-Arabic surname, have a Muslim first name but keep his father's non-Arabic surname?
Yes. It is allowed for Muslim to have a non Muslim surname or even name as far as it does not go against the faith of Islam. There are many pious Muslims who still carry a surname of their non Muslim grand fathers and it does not harm them at all.
New Muslim does not need to change his name or surname to a Muslim name or surname.
Wassalam