In ACP > Manage > Privileges, select the category you want to allow guests to post in, and give guests the "Create Topics" and "Reply to Topics" privileges.
Where can I see the PV history instead of
PV in this month and
PB in the last month? I also would like to see the PV trend in a longer period, e.g. 12 months.
Right now, we don't support that, even though we are collecting the data. It is on the list of things to do for an upcoming version