Odd Permissions Problems

I have a couple of mildly annoying permissions issues at present that I’m sure I could track down and fix if they were more annoying but I haven’t found the time or inclination. My first issue is with my local mail. I have Evolution configured to pick up the local mail spool and it works just fine. However, I can’t delete anything. It all just sits in the “trash” folder which presently contains ~1700 messages. I’m guessing it is probably because the mail file is owned by the root user. The second issue I have is with my Gnome Sessions dialog. If I want to add a program to auto start with Gnome, I can’t do it. I go to system / preferences / session and add in a new program in the startup programs. I hit ok, close the session dialog and if I reopen it it’s not there. As near as I can tell it attempts to add those startup items to /etc/xdg/autostart/ which I don’t have write permissions to as my normal user. So, what I have been doing is going to that folder, copying an existing entry (using su) and then modifying it to include the new startup program. It works but it doesn’t seem like normal behavior.