Scirra's license pertains to content you create in the Construct 2 editor.
Content, sold in the store, made in C2, by someone else, would have its own license.
So if you purchase something from the store, and edit it using C2 then you would be liable to Scirra's license agreement, if you make a profit off of it.
If you purchase content from the store, and do not edit it using Construct 2 you are only bound by the licensing of that content.