Regarding 'f' in borrowed words I think that what you say is correct for
rish at least. Thus we have mo froc 'my coat', co/ta Frainc 'Frank's coat',
mo fliu/t 'my flute' etc. but notice mo fhideal 'my fiddle' perhaps an older
loanword. This non-mutation of 'f' is common in other dialects as well.