Re: I broke the link to the home page
See this set of posts
I've had a very similar problem and just kept resetting the Home page in the Wiki area of Admin to the wiki page I really wanted and eventually it took (and I haven't seen the welcome install page since). Not sure why.
I really wanted it to have a blog as a home page (as it used to before I upgraded) but I've still been unable to do that no matter what I've set the home page to in Admin/General or in Wiki.
Now obviously Tiki is writing something to either the database or to an index page but I can't find either spot. If I could, I'd just go into MySQL or the right .php page and write it in by hand.