My suggestions, with a touch of humour, are about following rules. Rules are in bold text with Rule number at their begining.
16: Posting a comment in a long dormant thread (practice known as digging) for no apparent, practical reason other than increasing post count or just for the sake of digging is strictly prohibited. Repeated violation may result in a permanent ban from this website.
I like to suggest to make those threads you think are old/dormant 'read only'/'Closed Thread' automatically.
19: PakWheels.com allows all registered members to edit their posts for unlimited time. If a member abuses this privilege, a temporary suspension of all posting privileges will be imposed. Repeated violations will result in more serious action which may include a permanent ban.
How anyone can break/abuse this rule :D? Why not you give a link under posts to show edit history.
20: Members are not permitted to modify, change or remove any moderator edits from their posts. Violation of this rule will result in revocation of post editing privileges indefinitely.
Even better. Show moderator edits as non-editable/non-moveable/non-deleteable text when user edits it's post.
something like shown on this page: ( this is not an add link. goodle often take me to this site )
javascript - Is there a way to make a text area partially editable? (make only portions of the text editable) - Stack Overflow