of course, looking at what you have in your profile sending the merit is never an issue, is quite a huge task as you said to locate quality post within the Bitcoin forum, the community is quite a large one and is very much scalable.
You must be joking. The number of shitposts in this forum is so huge that merit sources would actually have to be ninjas to actually be able to merit all worthy posts and not overlook any.
I have no idea what you mean by "scale-able" in this context though.
I think you have a valid point from the point of view that 80 people will be tasked to view that number of posts per day. Not considering the fact that they also have other commitments on the forum to attend to. I for myself know that I believe that I have some number very merit worthy posts, since the merit system was implemented, however my merits gained so far was when I directly and deliberately applied/posted into one of those threads that were awarding merits for quality posts. Other than that, I would still be overlooked.
Merit sources are increasing. There is a method to apply as merit source as well. Also theymos has advised local board posters to apply as merit sources so that people who post in the local threads will also have a chance to earn some merits.
True the distribution of merit sources patrolling is having a lower "exposure" - but only time can tell how it will go.