Clydesdales/Athenas (200+ lb / 91+ kg) - Carbon fiber?

Being a clyde at 5'9" and 340 lbs will carbon fiber forks, chain stays etc hold up. Raliegh told my Lbs that their Cadent 3.0 is not recommended for someone in my weight range. Do you think it's just a CYA reply by Raleigh?

No...I think it's a Raleigh reply. I ride my Kuota since about 300 lbs. No problems yet (I'm down to 270).

I suspect they're covering that butts, but that would be reason enough for me not to buy the bike. You don't want even a 1 percent chance of a fork breaking on you. I've seen two forks break (one carbon, one steel), and it's a really bad crash. You're not going to gain enough to matter with a CF fork--a few ounces in weight, meaningless for you, and possibly a slightly better ride, which you can achieve anyway by using larger tires.
Incidentally, you really want to be looking for a bike that will allow you to use at least 700x32 tires. You have 110 pounds on me, and I don't use anything smaller than that.

I ride a Specialized Tri Cross Expert Double and weight 381. It has carbon forks and rear stays (not sure if that is the right term) and I don't have a problem.

Supposedly it's better to go with carbon fork that has an alloy steerer, they are stronger than the all-carbon forks.

Look at it as a question of what you feel is an acceptable worst case scenario: having a bike that's a pound or two heavier, or having something fall apart and cause you to crash.

I had a cromoly fork fail...

It was probably less about my being three hundred pounds and more about me using my new found ability to bunny hop 10 inches off the ground to bunny hop a two foot high tree trunk lying across a trail.

Now granted, in hindsight, the flaw in this basic math test seems obvious but when you are in your twenties, full of adrenaline and riding at 15mph down a wooded trail -- math skills are not always so proficient.

The things I did to that Rock Hopper under the guise of having fun borders on abusive.

Their engineers may know something, or maybe its just someone else in the company. But other companies, such as Specialized, Trek, and Cannondale are okay for uberclydes.

Why do you want carbon? I suggest you put your $ into the hubs/bb, seat, anything except making the frame lighter.