Another thing is that some of the choices for Marksman Ability appear far better than others. Close Combat Shot is nice but useless most of the time as long as you can make 5-foot steps. Maybe also give it the ability to make AoOs using your bow against adjacent enemies? Horizon Eye also seems a fairly underpowered ability since all you'd get is +1/5 to your maximum range for the same range penalty with no effect on anything closer than that. Far Shot is much better, giving you a longer range overall and reducing the penalty for hitting things closer to you.
Patient Hunter is a very situational ability, one that is occasionally useful on the first round of combat to wait for opponents to get within range, but otherwise I don't see too many uses for it, compared with something like Master of Serendipity which just screams Must Have. A bonus to initiative might be an incentive to pick it though. Master Ambusher is not as underpowered as some as them but still seems very situational and limited; maybe merge that with Experienced Sniper? Warning Shot has its uses but I can get the same thing for a +1 enhancement bonus on a magic weapon, and I usually don't bother with feats/class features that I can get from magic items. It should offer something else if you want it to be on par with some of the other abilities.