Congratulations KBN on the Class Representative position! I'd also like to thank you for penning your guide.
I play a Combat Sentinel and my observations are from a strictly PVE end-game perspective.
I agree that Combat has far too much RNG influencing ability use and can result in you "mashing buttons like a coked-out ferret" to maximize dps. It's liveable, but I'd like to see the RNG factor reduced in some small way.
While our role is specific in raids, our versatility could be improved slightly by increasing our AoE capability. This need not be by much: a slight increase in the damage of TST and Cyclone Slash (reduce the focus cost by one as well). This would put us on par with the favoured Gunslingers (XS Freighter Fly-by) and Commando's (Mortar Volley) as far as ability to deal with groups of adds without making us OP methinks.
My last observation relates to our last-ditch, save my backside ability, Guarded by the Force. While this is to be used judiciously, it seems in some fights that the 99% damage reduction is meaningless. One example of such a time is the explosion/surge at the end of Heirad's Lightning Storm. Our defensive cool-downs can mitigate the majority of the damage from Lightning Storm, but the last burst of damage seems to completely by-pass the DR granted by GbtF, in NiM mode at least. Further, other classes have abilities that make them immune to damage completely (Force Barrier, Dodge) for much less cost. Therefore, I would suggest that GbtF be changed such that it not only provides 100% immunity to damage/damaging effects, but also to all control and/or movement impairing effects as well.