If I am reading a message and hit the end call button to go to the main menu the next time I open messages it opens the message I was last reading. I don't want to have to hit the back button to go back to the inbox, is there a way to make the message folder default to the inbox?

No that is not possible. The end call button does not close applications. It leaves them running in the background. Think of it as 'minimizing' the email. If you were on your desktop and you minimized your email, they next time you opened that window, the email will still be open.

There is no setting to change this AFAIK.