is the headshot all there is available of the character, gender?

Why don't you just put it in your ToS that you are allowed to use it for whatever purpose?
Most artists have it like that.

No professional artist would allow a full-rights release of any artwork they produce, unless that was agreed upon by both the artist and commissioner. These kind of restrictions exist so the client doesn't take something designed by the artist, turn it into something like t-shirt logo and sell it, making possibly tons of money, while the artist who actually did the work receives nothing. Breaching a contract like that is essentially theft.

I meant that the artist has the right to commercially use their artwork, not the other way around.

Because it goes back the other way around - they are not giving me full right over their character/design just because I painted them, therefore I can't just use it for anything I want.

Although I do retain all rights over my artwork, so they can't use it without my permission either.

Oh oh, I misunderstood. Yeah, generally that's something that should be in the ToS and I agree. It's definitely something that should be well understood between both parties. It would be really messy if it went to copyright court over infringement. The likelihood of that kind of stuff happening on FA and the like is really small, but it's still important to consider.

with my luck in life, that is why i go for the safe route, and make 100% sure the other party is consent to what I'm doing with their characters. U_U might be a bit overkill for furry art, but it's still business, and I still want to do it properly.

Agreed! Safe route is the way to go. Making sure you've got all your bases covered is the best defense, in the event something like this does happen.

It's always better to take furry art too seriously, than not taking it seriously enough and then get hurt. I wrote a loooong, boring and complicated TOS full with legal language, and most likely I will never really need it, but if just ONE bad case happens, I will be glad I have it. ;)

And it's a general rule: If you make art for living, sooner or later you will have a case where you need a lawyer to bring someone on court. Maybe tomorrow, maybe in ten years... maybe you will be extremely lucky and never have to, but most likely that day will come.

When a character is sold, it is important for both the new owner and the artist that they can contact each other. Not only the artist may need permission for some things, but also the new owner is still bound by the artist's original rules, and so needs permission for some things.

For example, if either party wants to monetize the piece (like selling prints), they need permission from the other party.

Also, artists want to keep an eye out for abusers. Not only they may mistake the new owner for an art theft if they are not notified properly, but the new owner may actually abuse the license (for ex: start selling prints without permission of artist).

I added it to my TOS that if you sell a character I painted you MUST notify me in order for license rights to transfer - and then all the same stuff applies as it did with original owner. But this won't stop a careless owner from selling it without telling me, or a buyer from doing bad stuff because they never cared to look up my TOS, or maybe they don't have a clue about that they are bound by it if they buy a character with art I made.