As to the Governor and the mandate, I don't know Oregon law, but I am sure that whatever executive powers she holds, she is well within her powers to issue the mandate. I would also hope, as you noted, that she spoke with her health advisory staff prior to doing this, and that they (who are not the CDC) recommended it as a good course of action. If those things are true, then by all means I would agree with you that she is within her power and was listening to her advisors. As I said, you get what you voted for. If the mandate is unpopular enough it's possible she doesn't get elected again. I do find it odd that you think that one individual making the decision for all is better than each individual, who know their own circumstances better, being allowed to make their own educated decision.
The real reason, in my opinion, to mandate anyone regardless of vaccination, is because we all know that there are assholes out there who would just pretend that they were vaccinated and not wear one. The military tried allowing vaccinated people to go without masks, and even though the numbers reported for my unit were less than 50% vaccinated, you would be hard pressed to find anyone that was wearing a mask. The other part I find stupid about the mandate is saying homeless people don't have to. This is undoubtedly a population of largely unvaccinated people who are not exactly sanitary, and you are giving them a pass? It defeats the whole purpose of your mandate, so why even make it in the first place?
What I was against in your post is that somehow the guidance leads you to believe that what was written = mask mandate. It doesn't. I am also not anti-mask, I wore mine prior to getting vaccinated, and my job requires that I wear one indoors when around others, so I do, because it is what is asked of me. The same as if a business puts up a sign saying they are requiring masks, I will wear one in there if they made that choice, it's their business. I am also completely against the anti-mask asshats that want to go into said business just to start a commotion about their "rights" in the same manner that I can't stand the asshats who run around trying to police people who are not wearing one because they think it is the right choice.
What I do believe in is personal accountability. I don't think a mandate is required for outdoor gatherings if you've been vaccinated, because the CDC doesn't say they strongly or even remotely recommend it. They just want me to consider it if I find myself in certain situations.
Government leadership does not have to be authoritarian in nature for it to be effective. I can place the choice on the people and businesses, I can ask them to have smaller gatherings. When you do this, there is a majority of people who will simply do what you ask, rather than fighting back against something you mandate. No one should want or need a nanny state.