Corally:
Since there are so few 1/12 drivers in Italy, you may find this setup guide helpful:
http://richardchang.com/hobby.php?topic=112setup
Rich has been racing a number of years and his guide is a good resource.
Rusty:
I didn't offer any opinion about a thinner T-bar on carpet. But since you bring it up, it seems the newer generation of carpet used in the U.S. does not generate super high traction, even at big races with constant use, like just a few years ago. So a thinner T-bar in conjunction with the right tires, front springs and dampening (kingpin and rear dampeners) can be a faster way around the track. This is highly dependant on traction conditions.