[kubuntu] A few problems with Plank, help needed

Hello, I am setting up Kubuntu on my laptop and I ran into a few issues with Plank which I can't find any solutions for:

1) My icon theme (Numix Circle) doesn't show work on the Plank icons, instead the icons for apps pied to the dock are just the default ones.
2) When I try to put the trash docklet on the dock it's invisible.
3) I can't pin system activity to the dock as the option just doesn't show up.

Any help would be greatly appreciated.