I understand that FRCS is high-powered, but Thug and Blooded are not. Don't forget that those two feats are regional--to take them you've got to be from some particular place or have spent time there and (IIRC) have spent some skill points on Knowledge (Local). Still, even if you relax the feat requirements or use other similar feats from other sources or even certain magic items, some characters are going to have a really high initiative.
Let them.
At low levels, they will kick ass since many of the opponents they face will be flesh and blood and quite vulnerable to sneak attacks. At high levels, the sneak attack won't be so important.
Furthermore ...
a lot of people play initiative wrong. I discovered that I did at a Living City RPGA game (thanks Jim!) in which the following happened:
The PCs and the enemy spotted each other from a distance.
We approached each other, warily.
We rolled for initiative.
I won.
I did not catch them flat-footed.
At first I was angry, but in retrospect, the DM's ruling made sense. Initiative really occured when we spotted each other and said to ourselves, "Potential enemies." Since asking for an nitiative roll is often a trigger for combat, the DM did not ask for such a roll until it was clear that we would fight.
So how are you handling initiative? If you allow PCs to catch opponents flat-footed (or vice-versa) even after they are aware of each as threats, you might want to consider rolling for initiative at that first instance of awareness, or you might want to apply a logical standard to flat-footedness--if the opponent is aware of you as a threat, he is not caught flat-footed.
And as for the annoyance of a PC always going first...use monsters with improved initiative. Sure, the PC has a +10, but a few specters with +7 have more rolls to make-- one of them might manage to go first. The other thing you can do for such a fast character is to introduce a similarly fast rival-enemy-nemesis. Make sure that he's good at running away too.