I find this feature (viewing a users recent posts on the user's public profile page) really useful on other forums, I was just wondering why this is off by default in GZ? 

I figured it out it's the option "Make my personal RSS feed public" in the profile options, I'd suggest this could be renamed to be move obvious eg: "Show Recent Posts On Your Public Profile".

Also the current list of links that link to the topic, could this instead be a list with say the first 100-250 characters of each post with the link being to the actual post in the thread.

The alternative of course would be the ability to search for posts by user.

My 10c 

Edit: Here's an example
http://www.geekzone.co.nz/imagessubs/037bdd3ae0361f3a2163862dda4ab892.jpg