The reason those items are not listed is that they are not supported.
Plans
Calendar is just a very, very good web calendar.
Some of the items that you asked about are available features. The
calendar
is available for free, so the best thing you could do is download and
install it
and start playing with it. I can tell you that Plans is not as
sophisticated as
you appear to want when it comes to the security. It really is just a
simple
calendar, but for what it does, it is really the best out there.