
Abyssian |

Don't worry about feats to improve your Summon Nature's Ally extracts. Instead worry about bomb-related/improving feats. I recommend Point Blank Shot at 1st, Precise Bombs discovery at 2nd, and Precise Shot at 3rd. Use your critters as fodder and battlefield control since you aren't really going to ever have a high enough version to convert to Summon Monster (with the Planar Preservationist feat) for SLAs or other utilities. Especially if you change your mind and play an Elf alchemist, get Focused Shot after Precise Shot and start adding your Int bonus to damage with bows/crossbows.

Abyssian |

As I mentioned, I don't recommend Planar Preservationist, at least not early. The smite from Celestial-izing your summoned critters is pretty sweet but, like I mentioned above, the highest version of Summon Monster you're going to get is Summon Monster VI, and that's going to take some time. If you feel like it's a must-have, go ahead and get it, but get it when you have the feat to spare and your bombs are already extra-super-killer-bombs-of-death-dealing-killerness. That is to say, get it when you get a better bang for your buck than a bomb feat/discovery. You don't have so many extracts per day to get the full awesome god-wizard conjurer effect; you win the day by controlling the battlefield to get enemies together and then blowing them up.

Shadowdweller |
Use your critters as fodder and battlefield control since you aren't really going to ever have a high enough version to convert to Summon Monster (with the Planar Preservationist feat) for SLAs or other utilities.
The smite from Celestial-izing your summoned critters is pretty sweet but, like I mentioned above, the highest version of Summon Monster you're going to get is Summon Monster VI, and that's going to take some time.
You might want to, you know, familiarize yourself with the archetype better before offering advice ;)

Abyssian |

Please go on. What is the amazing benefit of the Planar Preservationist feat (be specific, please) in addition to the Preservationist archetype? At what level are you getting some earth-shattering, no-brainer ability?
Or is it that you believe that I'm only talking about the Preservationist archetype (you know, without the feat that I'm talking about) in those quotes from me? Could it be that you aren't aware of the feat that is strictly for the archetype that you are, and I am not, familiar with?

Shadowdweller |
Please go on. What is the amazing benefit of the Planar Preservationist feat (be specific, please) in addition to the Preservationist archetype?
I'll give you a hint, guy: Has to do with the level of Summon Nature's Ally and Summon Monster available.
Back to the OP: Your summons are going to be piddly before level 8. Planar Preservationist is a great feat, but won't add DR or all that much in terms of resistance until then. Therefore, focus first on bomb enhancement. A good line would be something like Point Blank and Precise Shot THEN the Augment Summoning (and useless Spell Focus pre-req) THEN Planar Preservationist. Extra Discoveries are generally an excellent way to go for an alchemist, but I think you're going to want your feats.

Abyssian |

Wow, my earnest apologies. In my reading haste, I read the names of the archetype's replacement abilities and, since the names actually use the same conventions as spell names, only glanced right and "saw" the corresponding spell.
What's extra funny (to me, at least) is that my just-turned-level-two PFS alchemist is (as of this scenario) a Preservationist, himself.
Iamadinosaur, I take back my specific reasoning for disliking Planar Preservationist and back Shadowdweller and my second comment that it is fine but to take it later, when there is more to be gained from it.