Ever since I started using email all clients I used (elm, pine, mutt) have started up with the first new message selected or had an option to do this. This seems like logical workflow. You open your mail reader to read your new mail. Evolution should atleast have an option to start with the first new message in the inbox selected.
I think this has no use when you filter your messages in to sub folders. So WONTFIX. You can use "magic-space-bar" feature, when you will press the space bar, it will navigate you through all new mails in any folder. You do not need to use any other key, only space-bar, it will scroll through message body as well. Try that.