You can do the search field with standard html, just copy the html for the search field and you should be golden.
The login and password fields, you could simply hijack the html from the forum too I believe... theres a mod at UBBDev to read the cookie information from the forums.
RecentTopics can be solved with the external use option on the content islands.
Forum news can be solved with either the UBBNews addon at ubbdev, or an RSS feed.
The shoutbox however doesn't allow for external use outside of the forums (not to mention several users have had issues with resource usage with it on large forums).
Top Posters can be used with external use on the content island.
You can edit most anything out of the forum by editing the template files.
