a question: what is hypochoristic?
and further: the Tom-, Tor- and Tot- (dutch) i don't recognize, can you give an example? (i'm dutch, you see)
exte should be etxe i guess
and to add: #-er# in especially German surnames can mean "habitation", like Leipheimer is from Leipheim and Luttenberger is from Luttenberg, etc.
oh, and -ma in Frisian means its patronymic, at least according to Meertens Instituut. See, mainly it is connected with first names, but later on they started to connect it even with placenames and professions, but when you see a Frisian surname with ending in #-ma#, it is often preceded by a first name.