I get the feeling you're showing a few unconnected photos rather than a photo essay about the event. Which is not necessarily a criticism, just an observation.
Selective colour doesn't rescue a shot, but it can give extra oomph. So if you're looking at a shot going "I like what it shows, but the composition is wrong", selective colour will rarely help you. So the Police hat... no idea what the shot is saying.
The last shot is better, but it doesn't really show any sense of purpose in the group - it's just a bunch of people standing around behind some horses. It might work better cropped and straightened to show the poster guy and two horses in portrait orientation.
I would either have gone for portraits of people at the protest, or an essay about the event. Also, with 12MP to play with you want to be zoomed out a lot more and cropping in post. When you're not looking through the viewfinder you really need to be capturing more than you need so you're not (eg) chopping someone's forehead off. That way tight crops are a choice not an unhappy side effect.
Just to show I'm not talking out my Cheney, here's some links to my shots. I tend to got for shots like
Dave at RTS or
Josh .Story/headline shots should ideally summarise everything in one shot, like
No WTO or
ANZ Kills or the inevitable
banner at the front of the march. The banner shot is necessary for the essay or headline and also where the UWA comes in handy - if you have a 16mm or wider lens you can get right up close and not shoot the people standing in front of the banner.