So there are 100+ people who get almost 33,000+ Merit every month which is almost 311 sMerit per person.
Merit sources do not get equal allocation of Smerits per 30 days, it differs per merit source, some get more whilst others get less, thus your calculation of Smerit allocation per person is not accurate.
That assures that merit will never be exhausted on this forum unless these 109 people stop accessing the forum and the sMerit(s) for others get's exhausted.
Exactly, and if hypothetically this happens Theymos will basically just appoint new merit sources and allocate them Smerits for the system to continue, the point is that Smerits can't run out because it is easy for the admin to generate it how they like.