These are questions that will have answers only after you get more time on the water. But if you are just entering the sport, regardless of the manufacturer I would be looking for a boat with the most stability... the most comfortable, and one that rolls with ease. Most play boats these days are pretty well refined and you can't go wrong if you stick with the ones that you have been looking at (kingpin, SX, etc). My point is that you want to progress quickly and you will get there that much faster if you have a boat that covers those areas the best.
If you want to stick with a pure freestyle type boat, the Jackson that best fits that catagory is the Star series. But I am not sure that you wouldn't be more happy with the 4fun.... You should try them both if you can. The Fun is a fantastic play boat, but really is a great river runner first. EJ took 1st place in almost every one of the competitions he entered around the US/Canada in his Fun until we got the Star series out just months ago. Now he is really going off with the Star. Check the website for more of that info www.jacksonkayak.com
But the important thing to focus on is really what you want to do. I myself suck at full on freestyle. Just a fact that I can't seem to do much about. The result is that I spend most of my life Creek'n or River Running. That is why my primary boat is the 4fun (at 6.1 195 I am at the mid to top weight range maxing at around 210 IMO). The SuperStar will make my free style better, but I am not sure that I will ever put that much into it compared to Creek'n.
If you want to give me a holler... feel free at 303-517-2621. I am leaving for Hawaii for a few weeks on next Thursday.