Ive been doing alot of training on the bike the last couple of months, I have also been bitten pretty bad :)
Im interested in what bikes you have been looking at, and what your price range might be? there are alot of companies that make high quality CF bikes.
have you considered Titanium? I beleive the material has similar shock absorbing characteristics as CF, but Is alot more durable, and there is definatly no weight penalty. check out Litespeed's Ghisallo frameset.. 1.7lbs
just a fun fact you may have already heard. Lance Armstrong rode a Litespeed Blade a couple of years ago repainted to look like carbon fiber, and with trek decals. That bike must be awful special that he disgused it to look like his sponsers bike.
Im not trying to say CF is a bad choice, alot of the pro's use it (sometimes because their sponsers give them no choice) but wat you are using it for makes a difference. If you plan on racing on it, go for Carbon fiber, but if it is mostly going to be used for training and commuting, you should go for aluminum or titanium, they will last much longer, remember the pros have sponsers to get them new bikes if theres start to show wear. Also, alot of pro's race on CF, cus their CF bikes are fast and light, but train on steel or aluminum bikes, because they put alot of miles in training, and carbon may take its toll. Titanium would obviously be te better choice, because of weight strength, and shock absorbing reasons
But aluminum bikes can be great too, I ride a FELT z80, It is aluminum frame with a few upgrades, CArbon fiber fork and seatpost to save me from those nasty shocks in the raod (aluminum is very stiff)
I have updated it to race in Triathlons, those geometrical modifacations may not be important to you, but I mention it to make the point that even aluminum bikes can be made very light, and race worthy.
1. how much storage do ou need? as a commuter, you probably need to wear a backpack of sorts, but for training, and even racing, I dont need more than 2 water bottle cages (compatible with almost eveery bike in the world) and a medium sized bag that uses velcro straps to attach to your saddle and seatpost, so you dont have to worry about Clamping anything to your CF
2. I consider ultegra level componets perfect for the commuter/trainer. they will last probably as long as you will, Dura-Ace are very high quality, last for a long time, work very cleanly, but ultegra will usually be sufficient. Dura-ace will make the difference if you are racing, or training every day, for long distances
3. Definatly get a carbon fork and seatpost. these are where the material is dafinatly a performance enhancer. Like I have mentioned before, CF is a good shock absorber. CF handel bars, bottle cages.. ect. can save you a few grams over aluminum, but dont make that much of a difference.
4. just make sure the fit ;P I only have experience with one bike shoe, and have nothing to compare it to,so I dont have much advice here