Where to start???
1st. find a bootfitter, there is a list at the top of the bootfit section
2nd. go see the bootfitter, there is a lot more geometry going on inside that new boot you just purchased, you will want to be able to use it to it's best advantage.
3rd. You probably paid a fairly large amount for these boots, It would be a shame to rely on the few words we could write in here, and think we could convey all the aspects for getting a good fit/setup out of it.
don't ski with your buckles and power strap loose and think that softens the flex---you will get shin burn
5th. For you to be competitive you will need your fore/aft balance checked, your lateral alignment set, determine and set your boot board ramp angle correctly, determine and set your boots forward lean correctly,(these last 2 items will determine your center of mass "COM" position). If I had your feet and boots sitting here in our shop I'm sure we could help, but over the internet
. Do you have custom insoles?
On the Olympics this week there is a commercial about a little girl gymnast doing the pommel horse event with a broken ankle, I think In 2004. She was successful, even with the injury--she overcame the pain and pushed through the punishment of doing that tumble---for the reward(she used up a ton of athletic ability credits to do that). I doubt she preferred to do it that way. What I mean to say is, don't hamstring your self by trying to set up your boots your self, there is to much involved. It will be like trying to ski with a broken leg,---a lot of pain and punishment.
PS, I wonder if the boots you have purchased are the right size??????????