ok, i want to completely redo a site that's been around for years. basically i want to scrap the old site as it no longer is ranked anywhere. i will want to drop pages already indexed and links interlinks will change. do i have to 301 each old page so say the index page or since it's not ranked well anymore, i can start over without the worry?
I would use the same page names etc. as if you make new ones you will be starting at ground zero since the new ones would not be indexed yet...i made this mistake once and went from 2000 hits a month to 0. this answer your question?
It's much easier if you do a slow change instead of an abrupt one. But then again, if you are starting totally fresh I doubt you are too concerned about your current visitors?
I would just build a whole new site, make a good structure from the start, and then upload it at once. I certainly wouldn't put redirects for every page, or your whole site will become too confusing to work on yourself (how to see the difference between an old and new page ?) Only if you see in your logs that a lot of visitors enter through a specific page and not at the main page, then you could make a redirect at that specific page.