Torque specs are so that threads on the aluminum bits don't get stripped. Has nothing to do with carbon bits being crushed.

Think about it... why would the torque spec, supposedly for, say, protecting a carbon steering tube, be printed on the stem? The stem doesn't know what steering tube it's going to be attached to when it leaves the factory. It's printed there so you don't strip the screw threads out of the stem. Has nothing to do with the steering tube. Ditto on the other bits that have torque specs written on them.

You can achieve the same thing by learning how to tighten screws without stripping the aluminum threads. You protect the carbon bits by not be so overzealous with the torque. Tighten just enough that things don't move when in use. No more, no less. If a joint is held by multiple bolts, make sure to tighten each bolt evenly. Quarter turn on one bolt; quarter turn on another. Work your way around so the stress on each bolt never varies too much. This is important always, but is extra important with the carbon bits. Much more important than torque specs.

And if your seatpost keeps slipping even after tightening things down, you likely need a shim. For God's sake, don't just continue reefing on the thing. Seems like most carbon bikes do, nowadays; the seat tube is so thin the manufacturers have less dimensional control over it. You can't risk the seat tube ID being less than the seatpost diameter, so they err on the larger side.