Re: Structure Tree
Besides the pointers and infos provided by Rick, you might also want to try adding the first page of your structure as the homepage of your site (that seems to be in your request).
See this doc page refering to "Admin home > General > Navigation (tab)":
http://doc.tiki.org/Navigation?structure=Tiki+Reference+Guide
The section related to "Homepage"
;){kind=link}
;){kind=link}