[WetWired]

The archive is hard-coded, last I checked.
To only show information if it is available, just use the variable in the condition. For example:

<if condition="$post['field5']"><div>Label: $post[field5]</div></if>

If the field is a number and 0 is valid, you may want to wrap the variable in is_numeric().

You can hide stuff from guests using

<if condition="$bbuserinfo['userid']!=0"></if>

For the external links, just set the forum to act as a category.

For the empty forum, use

<if condition="$totalthreads==0"></if>

Note that this condition will also be true if there are threads, but they are all too old to be included in the current view.