A Challenging Puzzle

Kathy, at Onestrangecat, posted a puzzle that she got in an email on Monday.  It was very challenging, and took me around two hours total to do it, but I actually found all 30.  I couldn't find the "bonus" answer, though, and am still searching.  Go take a look and see what you can do!  I told Kathy I'd send her what I found in an email if she wanted, but I don't think the answers should be posted.  It was hard, and it took some diligent combing. Let me know what you find.