The links on this page,

Good catch, I'm seeing the same problem, that's definitely a bug. I've checked the page for other tags, and it looks like it might specifically be a problem with tags linking to journal entries -- links to forum topics seem to work fine.

And when I'm trying this page http://www.gamedev.net/user/33873-apochpiq/ it does not have a `next`/`more` link.

I assume you're talking about the "journal"/"topics" tabs? They're limited to a small number of recent entries, but you can use the "find content" button in the upper right to access everything sorted by content type. Hope that helps you find what you're looking for until the bug with the tag pages is fixed.