Your credentials are everything when you use them openly, and even if you didn't, you're not a hard guy to find. Thats not why I dismissed your work. I dismissed it because you openly misrepresented yourself. NSA analyst =/= agent. When you put that forward, you're holding onto it to prop up your work. Why couldn't you just say "Latin teacher" or "author"? Are those not meaningful enough to distinguish you and your work? You didn't think so, so your credibility immediately comes into question.

Secondly, you were criticized higher in the thread by someone who could actually give you advice, but you were too arrogant to accept any. So you argued with them instead. You stated elsewhere that you welcome actual cryptographers to chime in. Have you posted this somewhere where that is possible? Mostly hobbyists and websleuths here, so I can only assume you're posting this to spam your blog. Again, goes to your credibility.

You made assumptions about the solution, as you did with the scarborough inscription. That's a huge red flag because it immediately suggests bias. You made his name fit by shortening it. Why would he shorten Arthur to Art? Why not mispell Leigh to Lee? Rick Gaikowski and Robert Graysmith can both also be shortened and substituted with 13 letters with Rick and Rob respectively. So you're taking liberty with the solution. Another red flag.

Sure, it's fun to speculate, but without credibility and a reliable, reproducable method of solving it, you're just another hack who thinks they are the guy to solve it. Maybe you are right about it, but your method isn't sound even by amateur sleuth standards. That's okay. We're all fallible.