I am setting up a new BES server and have a few questions. Using BES 4.1 with Groupwise

1) I have a few emails which I can delete on the Blackberry, no error message, just will not delete.
2) Emails are only delivered to my blackberry every 15 minutes, even though they are in Groupwise right away.
3) I have a IT Policy set to distribute every 24 hrs. What is the best practices on this? What do you give up by setting to never distribute? It is annoying blackberry popup to see that the policy has been applied every day. Can the popup be disabled?