Using a small altered image for a hand-made jewelry business.

Most likely your proposed uses are violations of publicity rights as well as a violation of character rights. In CA, both living and dead celebrities own the right to exploit for profit their own likenesses, and no one else does, and your state may have similar laws.

Protecting the likeness of a fictional character is more complicated, but if the name or image is copyrighted or trademarked, those rights are most likely owned by the tv or film studio that owns the motion picture or television program rights that created those characters, and those rightsholders could have infringement claims as well as claims for unfair competition.

Disclaimer: Please note that this answer does not constitute legal advice, and should not be relied on, since each state has different laws, each situation is fact specific, and it is impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue. This answer does not create an attorney-client relationship.

I am not a copyright lawyer, but my take is that if you are providing the photo you are likely violating the law, whereas if the customer provides you the photo and you provide the service of putting it into the pendant you do not. Even if it is a violation, I don't think that this is something that someone woould go after. Typcially, holders of copyrights send a cease and desist letter first. If you receive such a letter, I would then stop. However, again, this is not my area of practice, and if you are truly concerned about it you should consult a copyright lawyer.

Yes, it most likely is a violation of copyright, rights of publicity, and possibly other rights. Even though the image is being provided to you there is no such thing as an "innocent infringer" so you would also be liable. You could ask each customer to sign and indemnification agreement (do not try and write this yourself - you need a lawyer), but even this will not protect you 100 percent.

Whether or not you'd get more than a cease and desist letter really depends on who owns the rights to the image, but with the images you mentioned I can tell you that those rights holders are VERY aggressive in protecting their rights.