I would love an option where you could summon your Path Companion to join you in levequests if you choose to play solo.
(There could be a option to summon your NPC once you initiate a leve while you are not a member of a party, the NPC would join you for the duration of your levequest only. )
Your path companion would behave much like the NPC companion in FFXI.
That would be a neat way to level your Path Companion, optionally you could maybe even customize his gear.