Hi Crone! Thank you for the praise regarding our sounds and for buying the pack!
I do my best to mention the "Royalty-Free" as upfront as possible. But I'll pay more attention to the license going forward.
When you purchase our products, you have the right to use the sound as many times as you want without paying extra fees. You do not need to credit me in your work as you have the right to use it when you purchase the product, but you can't sell the work as your own as is. No one will be sued over using our sounds or soundtracks, we will not copyright claim anyone's videos.
If you wanted to sell some of the sounds or music as part of a soundtrack, that won't be completely denied either. Reaching via email and talking details through, I'm sure it can be done as well.
Hope this answered any concerns you might have had with the licensing.