For example, to become a Hero member, a user needs to earn 500 merits. On the other hand, he also has 250 spendable merits. On the current system, even a user who doesn't spend any smerits will rank up. So we can do something on that. Users must be forced to spend their smerits as well to reach the next rank. If he/she needs 500 merits for Hero rank, he/she also needs to spend 250 merits to achieve Hero rank. I don't think it's necessary to add any additional option for user profiles since each user can see how many spendable merits they have. This is my first suggestion; if theymos think it's reasonable, he could implement it.
I think I like this idea better. It's not a big change, but at the same time, it will discourage people from hoarding merit for whatever reason. I don't know if people who are not merit sources actually do hoard their merits because I've never understood the need to since it doesn't benefit you in any way, but if so many people are complaining about it, there may be truth to it.
I know the quality of posts in the forum has reduced, but what if the lack of merits is a part of the reason? I mean, if people saw that they might get rewarded for their effort, they might actually put in some effort, but when the merit doesn't circulate enough on the forum, I don't think people will be motivated enough.