I'd like to see more information on the slide to unlock screen, including missed calls, but would also like to get rid of the yellow missed call/received notification windows (as they slow things down significantly, having to tap the "start" button, render all the windows in the table, etc.) and would prefer e.g. an icon in the status bar which can indicate that you've missed something, then you open it to see what (e.g. a bit like Android does).

I added an additional solution as well.

One that could be coupled with or used in tandem with a few of the others here.

All I know is my solution comes from the annoyance I have of having to first read the notification saying I have an e-mail, click on it to be brought to the main accounts list, click again to go into the account then yet again to the inbox where I can finally click&hold to tap delete. And then have to tap delete, again.

That's like, a bajillion steps to many. We should be able to delete/reply/forward from the notification and that is what my solution is all about.