only one entry on star page, generate menu

Hi,
I am on the way to my own theme, but not very far :S
You can watch it here http://www.DreamFlasher.de/wp – There are a lot of issues left, which I can’t solve on my own:
– I always want only one entry per page, so on the index page there should only the introduction be shown, but nothing else
– if you click on any link (comments, show only this entry) then my design is broken
– For the menu I want some static links (index, imprint, contact…), the newest five as buttons and the rest in a dropdown box (seperated in two categories, and for each cat this order in two lines) (it works somehow with the Loop, I’ve to read here a bit more I think, but with the problems above, codex.wordpress.org didn’t help.)
I hope you can help me with this, I really want to have my webpage based on wordpress.