The error would should as this is meant to be your signature, but as you can't post links yet this would show until you have hit 5 forum posts. Then you can put in your channel URL into the signature section of your profile and then it will show your channel link underneath your posts. As for a way to maximise earnings there isn't really a sure fire way to do this as many things impact of your earnings for example the CPM amount, how many advertisers are looking to outline their products on your content, how many monetised views you get etc etc.
All I would say is focus on making quality content for now, and once you start to grow steadily you can always ask Freedom for a revenue share increase, and then they might increase this past the 60/40 share