I've run several of these in-character for people, and a few IC primal fights as well. :> As long as the group keeps moving, stopping for brief commentary and dialogue after every pull, you can reasonably expect to finish with at least 20-30 minutes left on the counter.
Remember that if someone's new, it helps to instruct them on the mechanics and tactics either IC or OOC. The meat of your RP can also take place before and after the dungeon (preparation/first meeting then aftermath/recovery).
A linkshell similar to Balmung's Finest would work best, with specified guidelines such as: no badgering people to skip cutscenes if it's their first time and they want to watch, agree to go fully OOC at a certain time limit, etc.
Remember that if someone's new, it helps to instruct them on the mechanics and tactics either IC or OOC. The meat of your RP can also take place before and after the dungeon (preparation/first meeting then aftermath/recovery).
A linkshell similar to Balmung's Finest would work best, with specified guidelines such as: no badgering people to skip cutscenes if it's their first time and they want to watch, agree to go fully OOC at a certain time limit, etc.