I don't think it is possible for this CC to Shred while having 5 combo points. I myself thought it was happening but it turns out Pounce Bleed has the same icon as Shred when it deals damage.
(shredder_2010_12_19a)
I found out about the Savage Roar nerf last night from a friend and nearly cried. I've removed it completely from the rotation.
I have changed Maim so it should be used ... less often (on moving targets with no DR, hopefully), which probably means Rip will have better uptime.