You quoted the answer to your own question. If you're using content made by the almighty "Content Gods" (i.e. Google or anyone Google gave godly powers to) then no, you can't use it for commercial means (or rather, you SHOULDN'T because even though it only says "may be protected" they'll totally sue you anyways).
Generally when I'm doing anything that requires a third party's product in any way, I choose that third party carefully. Either get explicit permission to use it (whatever "it" is) or create everything yourself (though going the latter route apparently doesn't protect you from other users of this service as they are allowed to do anything they want to your work and claim ownership of the piece they "made"). I wouldn't use this software to create anything for commercial purposes, personally, based on this ToS alone.
I see, you have a very good point. Contacting the original owners of the material should be the best way to get around it.
I tend to be extremely careful when using third party content as well, but they usually have a lot more clear TOS than this. And yes, I understand that I shouldn't seek legal advice, I should've used a better worded title. I'm looking more for people that have used it for what I'm specifying.