I just picked up a Scott Sub 45 for $540, new from REI (they had a 15% off sale, is that a decent price?). This is my first bike in years, but I was hoping to start biking, a lot more. I live in Minneapolis, so it's relatively safe area to bike in...and a LOT of trails.

Question 1) What should I have in my 'oh ****' bag for when I am riding? I heard flat tire fixer (quick pump/small, and rubber to repair?).

Question 2) Scott Fender kits, where can I get them? I definitely want those on my bike.

Question 3) I plan to bike with a camelbak backpack, does that ware on you after a few miles, or should I get a little bike rack as well?

1. Your seat pack should contain a spare tube, tire levers, patch kit, multitool, and CO2 inflator. On your bike your need a pump.
I'm sure others will add other items.

2. Why do you want fenders? Are you riding during or after rain showers?

3. Do you want the Camelbak primarily for water or do you want to use it as a backpack?
If you're using it primarily for water why not just carry two water bottles on the bike?
If you're using it as a backpack it may get heavy or hot on long rides.

I plan to bike after rain, yeah.

Can you leave c02 in the tires for a long time? Or is it for temp fixes? I was thinking of the topeak multi c02 and hand pump? or should I just get the Topeak Mini Morph Bike Pump?

CO2 is an easy way to inflate after repairing or replacing a tube. Beats pumping for 5-10 minutes with a small pump. You'll need to re-inflate the tire the following morning.
Get a CO2 inflator AND a pump to mount on the bike.

Sounds good, thanks I'll get that mini morph.

Depends on your riding conditions. My main riding is commuting to work. For a bunch of reasons I pretty much "have" to be able finish each ride. I carry an extra tube, pump + the associated tools, self-adhesive patches, a chain breaker, a quick link(for emergency Single-Speeding the bike if needed), spare shifter and brake wire.
If I knew I could easily have someone come and pick me up by car I'd probably settle for spare tire, pump and tire irons.

See no reason as to why you should need Scott branded fenders. There are several brands of generic fenders which should work just fine. But I'm all with you, unless you're in a dead-reliable climate(or racing), fenders make a bike so much more useful. Some carry the "racing stripe" one gets along the back without them with some sort of pride, I just think it adds to laundry.

If you're talking about one of those who are mainly a holder for the water bladder and a minimum amount of other stuff, I've never been troubled by that extra weight. Your back is very likely to get sweaty though.
Bigger packs can be more of an issue though, the trick to those is to carry them low. That gets the weight down to the saddle as opposed to down your arms/shoulders.

Rack or pack is a so-so issue, and if small enough mostly a matter of preference.
If big enough to matter, and if I plan to do a lot of out of the saddle riding, I prefer a pack. The weight of the pack will be a proportionally smaller part compared to my body weight than it will be compared to the bike's weight, so handling and feel will be less affected.
If it'll be mostly seated riding a rack is more comfortable, no sweaty patches.
Obviously there comes a point where you'll have to start loading the bike as well, riding with a full-sized backpack isn't much fun.

I was thinking of the Scott Fenders, because they'd look a little nicer then the uni's.

I;ll definitely have our camelbak then ... carry my keys/wallet/phone/tools/repair kit in it, and whatever we purchase/pickup at location.... thanks dabac