Question about Norton Family strength?

I'm considering buying a Norton Family account to moniter my son's computer access, though I have a few questions first. My son is somewhat tech savvy and I want to know if your product is secure. He knows how to use incognito mode, and I'm wondering if I would be able to see if this application was used. If I can see it was opened to browse, would I also be able to see which sites were accessed during this time?

 

  I would also like to know if Safety minder would tell me if the computer was started in Safety mode. I assume it couldn't immediately, but would I be told about it once my system has a regular startup afterwards?

 

   And one more question. Would it be possible for my son to create a new unmonitered account, or can this only be done with higher privellages? Thanks!