Force screensaver, timeout and password protect

[Peach]

I am facing some problem setting a default screensaver and then allowing the user to change their screensaver, but not able to disable the screensaver or change the time to a longer duration and prevent them from removing the password checkbox. It looks to me that I can have parts of this but not all. Can anyone recommend some tips? Thanks.

[HELLIAN]

Below are the settings that is based on user policy:
Policy Setting
Password protect the screen saver Enabled
Screen Saver Enabled
Screen Saver executable name Enabled
Screen Saver executable name logon.scr
Policy Setting
Screen Saver timeout Enabled
Number of seconds to wait to enable the Screen Saver
Seconds: 900

[Big Fish]

Do you mean to say that those are mandatory profiles?