Only thing I would really change is perhaps swapping your base Dex with your intelligence.

Only thing high intelligence does for you is give more skill points & bonuslanguages. You can afford to give up +2 skill points for +1. especially since the ranger get's 6 skill points per lvl which is the second highest rate in the game.

That 16 dex will boost up all of your dex based skills by one. The ranger is part skill monkey so that boost will pay off more. You actually won't be using the intelligence score for anythign with htis build, orther than possibly the Improved line of combat feets. Liek improved trip or disarm or whatever.

As for the Charisma thing, you're probably fine leaving it alone.