The two primary issues currently with the hunt system are monsters dying too quickly for players to get full credit and players being unable to get to their party member's location fast enough to get credit for a hunt. Adding the ability to summon party members to your current location for a gil fee and increasing the durability of said hunt mobs would most likely resolve these issues.

I understand some people want to complete hunts solo and that the above suggestions would make that potentially more difficult, but given how hunts are designed they are almost exclusively group oriented.