I've updated the zip with a fix for the All Achievements list
As for the resource usage, I've been unable to verify this with any of our big-boards users (except the ones that use vBSEO).
I've already taken pretty much every conceivable step to reducing the footprint this addon uses, so unfortunately I don't think there's much I can do about this.
However, some people reported a problem with the Leaderboards function. Can you try removing the leaderboards link from the templates and see if things calm down when people are no longer trying to access leaderboards?
Award Request / Nomination is a Pro feature as per the OP.
Fillip