As far as I'm concerned, guardian angels and spirit guides aren't the same thing.
Regarding your opinion about spirit guides, there's a lot that I don't know about them as well, so once I get out of my body and meet them, I'll ask them to address your questions.That might not be necessary though, perhaps you'll meet up with your guides before me, it all depends if you're going to connect with them any time soon.
Lol I'm sure you're not an unethical person and spies people.
And I agree with you,many people out there might know about,some might not believe, others might think it's not worth the effort, and some have their own reasons, hopefully all of the people that have knowledge will try someday.