I've come back and so much has changed, so I want to make sure I'm not breaking any new rules or anything.

Are overlays (done with profile code, like on my pets Thassarian and Romi for example) still allowed or must all overlays now be done through the custom overlays option that costs CSC? If what I have is no longer allowed I will definitely change it, but I am curious because I couldn't find anything by searching the rules.

Also: there is art of my pets that I bought from users on their profiles, but some of the users seem to have changed their usernames or removed their accounts, so the credit doesn't look right. Is it okay to leave the art there despite that?

Thank you in advance!

Non-official overlays are still allowed as long as you keep the pet's actual details (species, colour, etc) somewhere on the profile! But to make the overlay show up on other parts of the site (e.g. on the forums) you'd need to use the custom overlay option to do that. I'm not sure on the credit though.

you can still use the coded overlays. the only difference between them and the custom ones you pay for is that custom overlays appear on all parts of the site, so unless you care about that, you can just keep using the coded ones.

as for users that have changed their usernames, you could try asking around (maybe in general discussion?) to find out if anyone knows what they changed to, or if you're lucky said user might find the thread and answer you themself. you could also google "site:subeta.net (username)" replacing (username) with the user's old username to see if any of their old forum posts come up. that's how i've done it, at least.