This isn't the sort of thing that should be done at a Guild administration level. Building some kind of point system into the site infrastructure would inevitably lead to angst and strife of varying brands; in the point system you propose this negativity would end up being caused by people posting nonsense all over the place in order to rack up points, particularly by way of flooding the Spam section with massive gibberish posts, because people might not get that spamming garbage is still against the rules even in the section named Spam.
Anyway, point system aside, asking the admins or mods to make a bunch of graphics for this kind of thing is a little ridiculous. The already devote some of their free time to making sure the site doesn't turn into a heap of garbage, and in Mahz's case also time spent working on new site features that would actually have some function other than looking pretty, so asking them to devote even more time to implementing the word counter and point tracker and to making graphics (which many of them may not have the skill or knowledge to do with any reasonable quality) and then to make and maintain the shop thing is kind of silly.
The best way to have some kind of graphic reward for high activity or whatnot would be for it to be done by users, for other users. Maybe a shop in the Gallery where people can get a new set made if they've made a certain amount of RP posts or whatever. That would be a little bit challenging to manage right now since there's no search function and not much of a user post history, but it could still be done if whoever is running the shop feels like taking the time to manually go through some threads to count posts. Even that seems like a lot of unnecessary work to me, but hey, as long as it's someone volunteering for it rather than foisting it upon someone who is already doing work for free for the good of the site, it's all good.