it is an officer's job to put their own safety on the line to protect innocents
To nitpick here, the courts have upheld more than once that the role of the police is to protect society as a whole, not individuals. Likewise, they are allowed to arrest (with a warrant, if required) under probable cause and allowed to stop people under reasonable suspicion. Innocent until proven guilty matters more when it reaches the courts.
Also, I've been thinking about this, and it really makes no sense to me. How can someone protect society without protecting individual members of society, when society is just a collection of its individual members. How can someone be presumed innocent until proven guilty by law, if those most directly responsible for putting the law into action are not required to behave as such? What you are basically claiming is that the entire institution is nothing but a shallow facade of civility (which I actually wouldn't disagree with when stated that way).
I think I wasn't specific enough. The police need to protect society as a whole: that does include protecting individuals. It does not mean they must protect every individual with equal or any effort. Answering the second part, as well as the person who said pretty much anyone can be a suspect: a suspect (at least one they're bringing in) is a person who has
probably cause established against them. While people can become suspects more easily than they can be convicted in court, the purpose of being a suspect isn't to convict them at arrest: it's to stop potential threats to society.
This is where protecting society as a whole comes in: the best way to do this is to remove suspects from society. Habeas corpus, due process, and right to a speedy trial prevent this from being abused. Note that these are individual rights granted by a "higher government power" to balance out the role of the police, not something the police themselves give. Once a person is out of the hands of police and into the courts, this is where probably cause becomes lacking and we move to guilt beyond a shadow of a doubt.
About the summit moving to Camp David: Camp David has always been used for various things regarding diplomacy. I was in DC during one of the summits (I think it might have been a G20 summit) and it was pretty much a disaster trying to get around in the city. Sometimes more progress can be made when you don't have a city full of people yelling at you.
This also doesn't mean that you can't protest (specific points I hope! Protesting the whole summit would be silly). The world has become a lot smaller in the past 20-30 years. It might be easier and more effective to organize various protests in many major cities than one protests at the site of the event.