RE: Can you freestyle with a Carve?
It is definitely possible to learn new school freestyle while not being capable at the more bread and butter skills, just like lots of jazz players can play by ear, but can't read music.
Can be done and advisable are two different things. In the old days, when most boards were hard to jibe, a lot of people just went BNF and crash-tacked at the ends. Odd, I don't see them around anymore...I wonder why they stopped showing up?!
I agree with Ola's thought that some people can go straight to a Kombat, but that's probably only a good idea if you are able to get a LOT of time on the water or are a 'natural'. If you are a run-of-the-mill sailor, can get out sometimes on the weekend, do yourself a favor and get a Carve.
I disagree with Ola's suggestion of going to the Flare. It's a dedicated new-school, slidey, freestyle board (according to *B literature). What this really means is that you can't make it into a great all-around by sticking on a bigger fin (as many of the early freestyle boards could do).
Again, the Carve is a fabulous choice; i would strongly recommend the kinds of moves I suggested. Do that and you'll be able to go into the advanced stuff and be richly rewarded.