It depends on the type and extent of use, and much more; there is no straight answer.
Any designs or images you paint must be your own original work, based on public domain images, or properly licensed. But the original images you paint are automatically protected by copyright for the rest of your life and then some.
There is virtually no difference; term of protection is still based on the dates of the artist.
There are many legal sources for music and images, including fee-based, Creative Commons-licensed, and public domain sources.
Modern copyright law is based on the Statute of Anne, 1709.
Modern copyright is based on the Statute of Anne, 1709.
Modern copyright law is based on the Statute of Anne, 1709.
adaptive optics
Modern copyright law is based on the Statute of Anne, 1709.
Modern copyright is traced from the Statute of Anne, 1709.
YouTube and copyright owners decide what content appears on YouTube. YouTube decides based on the community guidelines while copyright owners decide based on copyright laws.
Modern copyright is based on the Statute of Anne, 1709, but international copyright agreements stem from the Berne Convention, 1886.
In any creative discipline, copyright topics can be divided into the materials you are using and the materials you are creating. A multimedia project can include dozens if not hundreds of copyright works, such as images, music, text, fonts, and video, each of them with one or more rightsholders. The creator of the resulting work may wish to control the copyright of the project, but may have significant difficulty based on the agreements with the rightsholders of all the component parts.