I would also like to know whether to use HSB or HSFC. Or is that just used for service QOS? Throttling bandwidth is why I bought the software as well.
To answer your question helloton, I would imagine that would depend on what you want to do. Limit bandwidth for the entire masks set of IP's to a certain speed or limit each computer within the masked set of IP's. That seems pretty clear to me.
I think netmask priority is total for all computers that are in the range.
For Packet Scheduler I have mine set HTB and it works fine. I leave it HTB because the help says:
"In other words, HTB is useful for limiting a client's download/upload rates, thereby preventing his monopolization of the available bandwidth."
According to the help it looks like HTB is best suited for the speed limiting feature of DD-WRT although I am not sure of the differences myself.