Carbon bars aren't too great at ironing out rutts and bumps as they don't actually provide any suspension: they're more suited to smoothing away 'road buzz' (that is, small but fatiguing, high-frequency vibrations).
Suspenion seatpost is low-maintenance and, as Sloe says, good at stopping you (no offence, but the biggest mass on your bike...) from being flung skywards if your rear wheel hits an unexpected lump.
A well thought out riding position, decent grips (that also perhaps support your palm, e.g. Ergon, Specialized), peeled eye-balls to see what's coming and a little bit of riding finesse are all more important than springs up front.