Thank you for your help. All mentioned bannings and deletions have been taken care of.
The issue with locking pages is, unless there's a super-intelligent filter able to detect vandals/spammers and prevent them from editing (which is unlikely), we can't flip the switch for the entire Wikia database to be only accessible for editing by administrators. Not all registered users are vandals; some can be contributive!
However, the only effective and feasible option we could switch the Wikia to is the option of preventing IP edits, which, I believe, is already put into effect.
We still have a problem with the images on this wikia. https://bubbleguppies.wikia.com/wiki/Special:Images i'm seeing like 5% Bubble Guppies. and 95% SpongeBob photos. And it's been going on for months now
Actually, The Backyardigans was on Nick Jr, then it got removed from Nick Jr, and then it came back on Nick Jr! I saw the Backyardigans on the Nick Jr TV Schedule!