I just looked at the suggestions one by one. ON blog, We already have Tabs in Navigation bar for each category and apart from that on the side bar, you can find the most popular posts of blog , plus recent posts and Random Posts in bottom.
I avoid putting that Archieve link on blog which shows posts by month as IMHO it doesnt add any value to the blog either for a lazy reader or non lazy one.
If someone got anything specific, I would love to hear that. What more can be added ???
Regarding Forum, the view you were talking about, shows you posts/threads since you logged in last time. By default, the forum already shows posts/threads over the total period of forum.
Anything specific and I would be able to help everyone in a better way.