As long as it is non-commercial, feel free to use my music. Please add an attribution in your description. A simple link to my website would work. Also, don't forget to share your project with me! :)
I've used various loops from a vast source of soundpools in my arrangements. Considering that a lot of people use the same soundpool(s), such warnings are expected. Certain arrangements I've made and uploaded to sites like YouTube have received similar "warnings". Just click "Accept"
As mentioned in the answer above, I often use loops from the same vast soundpool that is available to many others. If it sound similar, chances are 'XYZ' is tapping into the same soundpool(s). My favorite go-to sources are Magix and Apple. In fact Spiritus was created entirely on Apple's GarageBand using the available loops.