This is odd, Chishire.
I would reverse the examples you gave. In the usage I know,
clitics have no separate accent, but form an accentual unit with another word.
Procitics "lean forward" onto the following word: d'habitude.
Enclitics "lean back" onto the preceding word. She'll.
I don't know which I'd use for the
'n in "Rock'
n'roll". It would depend on whether it seems more closely related to "Rock" or to "Roll". I can't tell and my dictionary is no help. Maybe someone else knows a term for a "midclitic"..