Removing an shortcut works the same, just drag it off the dock and it’s gone. Clicking with the right mouse button on the dock brings up an menu in which you have some more options for adding shortcuts and to add a separator. You can also activate some other options for the dock like an auto hide function.

Personally i find that rocketdock is too big like this, and you can change this by going to the settings button. Then in the icons field you can select the size of the icons in normal state and when you hover over them. In the position field you can enter where the dock is positioned and on which screen if you have more then one. And on the style field you can select the style of the dock and control the text under the text of the icons.

Creating you own style isn’t very hard either. You can look into the styles map and take a look at the .ini files that are listed there. You can also follow this tutorial which provides a good start if you want to know more.