First, register with the CPSC as a small business. Then you'll be exempt from testing yourself, and can rely on the suppliers of your materials third-party testing (if you can find it!).
Fabrics, thread, yarn, trim, elastic, velcro, etc are exempt materials. As long as you are registered, you don't have to worry about testing these items, as they have been deemed highly unlikely to contain toxic substances. So your crayon case, and possibly your superhero capes (you don't currently have any listed) are very likely ok...though I don't know what regulations would apply to something that fastens around a child's neck and I don't know what closures you use. I know there are regulations regarding sashes on girls dresses, as far as not hanging down past the hem of the skirt, so I don't know if there's something similar for capes.
Your iron on ties would need testing, or a certificate of testing, for the heat-n-bond. I think.
It's worth setting up an LLC (with separate bank account, if you want to actually be protected, at least in Colorado). And I have seen someone on here say they got liability insurance for about $35/mo, which isn't too bad. At least do the LLC, since it doesn't cost too much to set up.
And I don't know how things work retroactively. I was lucky enough to only have sold some spare fabric before I discovered CPSIA.
