You can get the functionality of folders in Gmail by doing a small setting. You should add a filter, then whenever a mail comes from a specified source or with a particular subject then it can be skipped from inbox, added the desired label and archived. So that it will not be shown in the Inbox but will be present at the specified folder.

Try it!
If still have some problem ask me I will post the step by step method with snapshot.

hehe I remember this topic when it wzas first active or there is some similar topic of this sort. I do not quite know whether or not I said this already but you can write your own addons extensions and other sort of usuful programs if you know bits and bytes of javascript and understand how hall thing work. You should read the book called Gmail Hack it will prove to be quite usuful and helpful. So eventually you could add all those thing you miss.

P.S. there is site where you can write your suggestuoins to the google teams and they take it really seriously.

Good luck with hacking gmail -> note that hacking here means not as making trouble but instead working with code. hopefully you got me there.

Allow middle button (wheel) clicks in the inbox to open messages in new tabs. Very annoying, sice I am used to having only 1 Internt Explorer or Firefox window open at a time.