If my list of games looks like this, is it 100% not used keys?

Yes

I will say usually yes, there have been instances where I have clicked "reveal key/gift link" and next time I visit the key is hidden, but it always corrects itself upon refreshing. However, that is rare and it can be safely said that the keys are unused if it looks like that, especially after refreshing.

Hmmm. Did you redeem the games and them looked at your library and some of them still show as unredeemed? You know you won't get "free" duplicate keys, right? HB keys page sometimes has a shot delay after redeeming some keys, you need to close the tab and refresh the page as ElocinTygr above me already stated.

The best way to be sure is to go to the purchase page of the said bundle and then you are sure. For me that list sometimes takes a day or 50 refreshes of the page to be accurate.. :/ But the purchase page is always 100% accirate :)

Ctrl+F5 a few times to be sure.