The ORC HORNBOW is slightly better than the Longbow. Humans can pick this up with a feat at first level, Half-Elves can pick it up with the Ancestral Arms alternate racial trait, and Half-Orcs treat it as a Martial weapon .
Otherwise your feats look pretty good. I don't know that you need Iron Will - you have a strong will save progression and you're a WIS-based class. But if you feel like you're failing saves then take it for sure.
What level are you planning for? A +2/+3 weapon with only a +1 cloak seems ... weird to me. Why spend ~10,000gp on another +1 to hit and damage when your Cloak only costs 3,000gp to give you another +1 to all saves .
Also what are you thinking for stats?
I would spend less money on the bow, honestly. Probably leave it a +1. You do still have Sacred Weapon that can add enhancement bonuses to your weapon. At 8th level, this goes up to a +2, for a swift action. Having an "Adaptive" bow and getting a decent Strength modifier through a belt could prove cheaper, and would help in other ways.
Get a +2 cloak now, and save the rest of the money for Gloves of Dueling to up your Weapon Training bonus.
Are you taking Iron Will to get a Familiar through Improved Familiar Bond? That would be cool.
Half-Orc's can get Endurance for free via Shaman's Apprentice, and the ever-popular Sacred Tattoos/Fate's Favored combination for a +2 luck bonus to all saves. With Darkvision, and a possible bite attack, it is a solid start for any character/class/role... floating +2 ability score adjustment on character creation makes anything an option.
If you choose to replace Iron Will... Snap Shot is a good one, and you already have the prerequisites met with your other feats. Improved Initiative is always good. Extend Spell would help some of your buffs last longer.
A human warpriest can’t take exotic weapon proficiency at level 1. The human has an option to trade their feat for exotic proficiency though.
I didn't notice Deadeye Bowman. Honestly if you're worshiping Erastil I'd probably go with a Longbow anyway. It's slightly less damage, but it's more flavorful and Deadeye Bowman is a good trait .
Also Melkiador is right - Warpriests don't qualify for Exotic Weapon Proficiency at 1st level, I mever noticed that +1BAB prerequisite =P
For other feats you could go for Improved Snap Shot, or I always thought Overwatch Vortex looked fun.
You could also spend some feats on the more cleric-y side of your class. DIVINE INTERFERENCE is a phenominal feat. It's better on a cleric but it's still great on a Warpriest.
And yeah there are general feats like Improved Initiative thst are always good.
Could also trade Iron Will for Deific Obedience, and take Diverse Obedience at 9... Erastil offers some okay boons. And you already have the major archery feats out of the way, plus you still have bonus feats for anything else you may need (like Clustered Shots).
Divine Interference requires CL 10, anyways, so that can wait until 11. Extend Spell wouldn't be bad at 13, if you don't have anything else to put there. You already get Quicken Blessing for "free".
The Iron Will/Familiar Bond/Improved Familiar Bond path could be fun, and might offer some actual utility once it can share spells... Improved Familiar would make it a 4 feat chain, though. But having a little friend that can deliver your touch spells, and possibly even use wands, could prove very helpful. If that is worth it, only you can decide.
By level 10, you should have the Gloves of Dueling, and that will be a huge help in both accuracy and damage. So you should feel relatively confident by now spending feats on other $#!+...
What excatly dose Deific Obedience do? I mean what would this give me?
Depends on the deity.
So if we assume you go Erastil then ...
OBEDIENCE
Plant five seeds in fertile earth, spacing them out in the shape of an arrow. The seeds may be those of any plant that can potentially grow in the region, though edible plants are preferred. The seeds don’t need to be from a type of plant that could thrive in that soil—all they must have is a chance at survival. If no suitable earth exists, place a small bundle of seeds (again, those that grow edible plants are preferred), a small bundle of preserved food, or a quiver of arrows in a place where a passerby might see it. Mark your gifts with Erastil’s sign, and say a prayer for the health and safety of the communities in the area and those who may be in need of Erastil’s guidance. Gain a +4 sacred bonus on Survival checks.
But you also gain the EXALTED benefits as you level up.
AT 12 HD
1. Animal Friend (Sp) charm animal 3/day, animal messenger 2/day, or summon nature’s ally III 1/day
AT 16HD
2: Hunter's Ally (Sp) Once per day as a standard action, you can summon a pair of hound archons. The hound archons follow your commands perfectly for 1 minute for every Hit Die you possess before vanishing back to their home in Heaven. The hound archons don’t follow commands that would violate their lawful good alignment. Such commands will not only earn refusal and scorn from the hound archons, but could cause them to attack you if the command is particularly egregious.
AT 20HD
3: Communal Table (Sp) Your devotion to caring for your community allows you to evoke Erastil’s divine bounty to feed your friends with a banquet of cooked game and simple beverages. Once per day, you can use heroes’ feast as a spell-like ability. Creatures that eat from this communal table, a process that takes 1 hour, gain a +2 sacred bonus on attack rolls and Will saving throws instead of the usual +1 morale bonus. Whenever you cast this spell, choose one teamwork feat; you may select a new feat every time you cast this spell, but once it’s cast, your selection can’t be changed. Anyone who eats from the communal table gains the benefits of the chosen teamwork feat. The benefits of the heroes’ feast, including the bonus teamwork feat, last for 12 hours. A character doesn’t need to meet the prerequisites for a teamwork feat granted through this ability.
It also grats you access to one of three prestige classes: EVANGELIST, EXALTED and SENTINEL. If you take Exalted then you gain the Boons above at earlier levels (as well as the other benefits of the prestige class), but if you take Evangelist or Sentinel then you lose those benefits and instead gain another set of Boons. Even a single level of Evangelist or Sentinel will change the list of Boons you receive.
AT 12HD
1. Family's Bond (Sp) cure light wounds 3/day, shield other 2/day, or prayer 1/day
AT 16HD
2: Twin Fang (Ex) Once per day as a standard action, you can summon an exact double of your animal companion. The double acts and thinks like your animal companion in every way, and obeys your commands just as the original would. Your original animal companion and its double understand and trust each other perfectly. The double remains for 1 round for every Hit Die you possess, and then vanishes. If you don’t have an animal companion, you instead gain the ability to use summon nature’s ally V as a spell-like ability once per day.
AT 20HD
3: Faithful Archer (Ex) You are particularly skilled at using Erastil’s favored weapon. When using a longbow, you add your Wisdom bonus on attack and damage rolls against targets within 30 feet.
AT 12HD
1. Sureshot (Sp) longshotUC 3/day, deadeye’s arrow 2/day, or flame arrow 1/day
AT 16HD
2: Tough Hide (Su) When you wear armor made from leather or animal hide, the armor provides an extra +2 armor bonus to your AC. This bonus improves the normal armor bonus granted by the armor; in other words, it stacks with the suit’s normal armor bonus. You also mystically subsume some of the qualities of the animal that gave its life for the armor. Gain the scent ability with a range of 30 feet while wearing armor made from leather or animal hide.
AT 20HD
3: Farmer's Bond (Su) Your time spent cultivating crops has given you a bond with plants. You can cast speak with plants 3 times per day. If you spend at least 1 hour during the day in direct sunlight, you don’t need to eat that day. Finally, you become immune to poisons ingested from whole plants (not distilled poisons, such as assassins use) and any poison from attacks or effects generated by plant creatures.
Alternately there's the DIVERSE OBEDIENCE feat which lets you mix and match them a bit.
Yeah, I like Diverse Obedience at 9 because it speeds up progression and allows you to choose all willy-nilly each time...
For Erastil, I like the Evangelist 1st boon for Prayer 1/day, the 2nd Sentinel boon for the AC bonus, and the 3rd Exalted boon for the Teamwork feast thingy... if you have an Animal Companion, the Twin Fang Evangelist thing could be fun, but that would be an entirely different build (probably involving Divine Commander for a Mount).