It is good that you raised these questions. Your use of sports teams, childrens' characters, and images of famous singers violates various intellectual property rights, including copyrights, trademarks, and rights of publicity. This is clear, blatant infringement. You could be sued for civil violation of copyright law (images and characters), trademark law (team names, logos, and character names), and rights publicity of the singers and others. If you sell these at craft festivals in small quantities, this may not get the attention of the owners of these intellectual property rights. But if your business grows or if you keep selling these items at many shows, eventually, this illegal conduct will catch up with you, and you will be sent cease and desist letters and you will be sued. Defending these law suits is expensive---think tens of thousands of dollars. Further, copyright law provides copyright owners the right to obtain statutory damages and attorneys fees, and your damages can range from $750 up to $150,000 for each work that you infringe (depending on whether your infringement is found to be willful---and it surely is willful---this is bad faith, blatant infringement. Don't do it).
Anytime someone tries to profit by associating their products with famous sports teams, celebrities, singers, or famous companies, they are engaging in illegal conduct unless they have permission to do so. You are creative and talented---make your own designs, and sell them on the merits of your creativity---don't piggyback on the fame of others. This is actually one of the profound problems in our economic system---people take the easy way out rather than doing the hard work of creating a valuable, innovative, new product. As President Obama has wisely and repeatedly emphasized, we need to strictly enforce our intellectual property laws to provide the proper economic incentives to reward originality and reality rather than people who try to make easy money by taking advantage of the groundwork laid by others.
The use you describe is likely copyright and trademark infringement, and also a violation of the right of publicity of the individuals who's images you are using.
How does paying up to $150,000 per item for copyright infringement strike you? Add to it court expenses and attorneys fee! These companies you are infringing paid millions of dollars to develop a reputation for their trademarks and copyrighted images. Those images are now famous and associated with them. Use of them implies you are licensed by them. You admit you are not. Rather you are taking their images because of that reputation. That is wrong and immoral and you should have to pay for your sins. Another reason this is wrong is that trademarks are an indicator of source of origin and quality control by that source. If they let fly-by-nights like you make stuff without them exercising quality control then the trademark would not serve the function of showing either common source of origin or quality control by that source and the trademark owner has to stop it or place their trademark rights in jeopardy. Stop doing this, it is illegal. If you are also copying their products then you may be committing a crime as well and have your products subject to confiscation and destruction in a raid.
The images are also likely copyright infringements. If you don't know enough not to use sports logos, you likely do not know enough not to use copyrighted character images. You are also likely violating publicity rights of the singers whose images you are swiping.
This same question seems to come up about 50 times per year. It is amazing how many people don't realize stealing someone else's image is wrong. It is not much different in nature from shoplifting and then selling the stolen items - you are taking someone else's stuff without paying and then trying to make money selling that stuff.
L2BL: Unauthorized application of trademarks and copyrighted images to craft items for sale is illegal and can get you in big trouble.
