I believe there is a lot a of interest for the first option if less technical users on the site think about what I am saying and if it impacts them. I am curious as to how you define "chronological" order for news items that are posted by users. If it's simply based on the original post time, then you might as well fix it to sort by the last-post, as I believe newer news items will generally be on the first page alongside "hot news item." If you would rather leave the sorting as-is, can you at least ajax a call to sort by last post, and when a user (me in this case) clicks to sort as that, chances are it the response is ready and the sorting will be much faster than having to wait for a whole new page load, after just waiting for the chronological/regular sorted version to load.

To the second one - good to hear. I will keep an eye out for it.