BMWRT said:
1: what is the consensus for riding, as in how many times per week. Everyother day, every day etc.
Whatever your body can handle, of course taking recovery into account. You could do a relatively easy ride every day, or maybe do a few small rides during the week to 'save up' your endurance for a big ride on the weekend, etc. All depends on your current level of fitness, your target fitness, how much time you have, the kind of terrain where you ride (flat, windy, hilly, etc.) and so on. You'll find your own comfort zone soon enough.
One thing's for certain though, whatever schedule you 'aim' for, you need to ease yourself into it over a time period.
2: I have looked and cannot find anything about the longevity of carbon bikes. Do the fibers break down over the years. I have had My current ride for 16 years but I am close to pulling the trigger on a full Carbon Trek. Can I expect to get the same longevity from a carbon bike?
With modern metallurgy and engineering, generalised assertions based on material alone are close to useless
The old rules of thumb no longer apply; manufacturers can design steel frames that are short-lived featherweights, aluminium frames that last a lifetime, and carbon frames that are super stiff and bone-jarring.
With CF frames, it's usually not the carbon fibre itself that dies (delamination), but where it interfaces with other parts: the lugs joining it together (at least, the interface between the lugs and the carbon tubing), the interface between the carbon frame and metal bottom bracket shell, etc. This was generally only a problem with early carbon frames, and I'd expect any reasonably modern race-spec carbon frame to match, if not exceed, the lifespan of a modern race-spec frame made out of any other material.
As CF is not a metal, it has a different set of strengths and weaknesses as far as care and long-term durability is concerned. Bike companies publish their own set of guidelines for maintaining a carbon frame.. usually covered in a thick layer of legal-ese CYA stuff as damaged carbon fibre isn't obvious like a bent metal tube is. Trek's is linked from here:
http://www2.trekbikes.com/us/en/Inside_Trek/Owners_Manuals/Index.php
Carbon doesn't crease, ding, bend or buckle like a metal frame would under impact: it'll hold perfectly strong up to its limit, and then it will break. (If it gets a severe whack near, but not quite up to, its limit, some microscopic deformations might occur which will weaken that part of the frame.)
Where that limit is depends on the design and lay-up of the fibres. Generally speaking though, they are a lot stronger than first appearances. (IMO, if you were in an accident serious enough to snap a carbon frame, the broken frame will be the least of your worries)
3: Any real difference between a 10 speed and 9 speed ($300 difference, same bike)
simple answer: the right-hand shifter has one more click in it
long answer: compared to 9 speed, you can have closer spaced gears while still having a similar gear range. Or a wider gear range with the same spacing. Also, 10 speed systems being newer, have some internal mechanical improvements here and there (like in the indexing/ratcheting systems, etc.) that the engineers have improved from their older 9 speed designs.
Is it worth spending $300 more for? Personally I'd spend that extra on something that would make a more significant difference to the ride, like perhaps getting a better wheelset. Also, 9 speed consumables (chains, cassettes) are cheaper, and you can always upgrade to 10 speed later on should you feel the need..