Your router is pretty basic, you will be even more confused by devices that have the ability to really restrict traffic. Yours pretty much can control upload rates and most people have issues with the download.
Many router manufactures I think include lots of confusing stuff in the QoS to hide the fact that the QoS in most routers does almost nothing.
Things like DSCP packet remarking is a total waste of time to include in a consumer router that is connected to the internet. No ISP will honor any packet marking and removes them. The are only used in a private network where you have total control and nobody is going to use devices like this in a private network. Lots of router manufacture include the feature even though it is...