Just a thought, and if it already exists, I apologize in advance.
Couldn't it be possible, for the characters in a party to 'latch' themselves to a 'leading' character, so that only one person at a time in a group has to handle movement?
It would make running your alts so much easier, as well as open up opportunities for 'shuttling' services, as well as be one more way to encourage social interaction.
Another Party Idea:
Sometimes we drift to other areas away from our parties, and then make plans involving the whole party, and have to take long steps to come back together. Yes we have the return to Castille thing, but what about a 'Zoom to Party' feature? This would allow party members to just select which member to zoom to and then go there. This would likely incur some kind of cost, but could save time-limited players a lot of time.