Please allow us to exchange surplus guild skill points to unlock higher tiers of guild missions.

Some guilds are small and wish to remain so, but still have higher caliber players who would prefer to do higher requirement missions. Allowing said guilds to exchange surplus guild skill points for permanent access to higher size guild missions, like 50/100/150 for permanent Medium/Large/Extra Large seems like a reasonable rate to me. They're high amounts, so only guilds that are already doing a lot of missions will unlock them in any decent time, but not so large as to make it too prohibitive.