2) if users have the ability to add their own items to the list, you are going to need a way to monitor the lists for duplicates or items that are not specific enough - (example, iPhone) or items that are wrong (iPhone Blackberry). Since you are starting with a clean slate in terms of products, it will be most useful to you to ensure that the product names are kept as clean as possible, this will make it MUCH easier to integrate with a price service if you plan to monetize it that way in future.
3) I'm not sure what the 'revisions' button is supposed to do (not technically, I mean in terms of usefulness to the site). I was able to rollback someone else's review to a previous version.
4) Product lists can grow to be quite diverse and you will need a way to categorize the lists the same way that products are grouped into lists. For example, you may need an Electronics category where all PC's, cell phones and GPS's are listed. And futher on you may need to break the cell phone category into 'Smart Phones' and 'Cell Phones'. Advice for this is that if you do plan to monetize by connecting with a price service then map your categories to that of the price service because it will be easier to sync up your products later (unless they really don't match your categorization in which case you will need a way to match them up behind the scenes.)
5) Don't know how you would approach this one, but when I went to 'Blogs for Entrepeneurs' and clicked on 'Paul Grahams Blog' I could see that the response was positive so I would want to check out this blog. If I didn't know who Paul Graham was I would need to then google his name to find his blog. It would be nice for items like that if the person who creates the item could add some text or blurb about it. But I'm not sure how that would translate when adding an actual product that is not a blog.
Hope that was useful :) Good luck with it!
[edit: spelling]