level 30 and can't post in forums

[Enkidoh]

It has to due with the fact that gold sellers will be able to spam their stuff on the forums. RMTs do not generally use their lvl 50 characters or accounts to spam in game or on forums as they are trying to keep a low profile on these accounts. In the TOS, if I'm not mistaken, you can actually be banned in game as well based on the severity of your forum violation. By not allowing low levels to post they prevent spam or advertising accounts from filling up the forums as seen in other MMOs.

It actually wasn't added because of RMT, as the forum never had these restrictions originally when version 1.0 was running (and the 1.0 forum never had any RMT advertising their ill-gotten gains from what I was aware). These restrictions in fact were first added to the ARR Beta forum, as there was a massive influx of new testers between Phases 2 and 3, sadly it resulted in a sudden increase in the amount of trolling and flaming going on, both from new testers and Legacy members and Alpha/early Beta phase testers. It became such a sordid affair that SE hurriedly introduced posting restrictions in an attempt to bring some order to the chaos.

No doubt the Beta forum incident spooked SE and thus they decided in order to head off any possible repeat of such nonsense when the game went live, they added similar restrictions to the official FFXIV forum, which up to that stage, was for version 1.0 only (and in fact was only accessible if you had a 1.0 account).

Yes, some of these restrictions can be annoying, but they're not to hard to deal with (the 1000 character restriction is easily worked around by simply going back and editing your post, like I just did ).