Don't know if this has been suggested before but I thought this could be a worthwile addition: Replace the functionality of the reply links with the tagging system and add a link that allows people to quote posts.
Bottom of the postbit could look something like:
#184 Like Quote Reply
Meaning: If I click "reply" on the above post instead of "quote" @masterchief is tagged, if I click on the new "quote" link the reply contains the quote as by xenforo default. If something about my explanation is unclear and you want me to illustrate what I mean let me know.