Is there any risk of freezing your actual bitcointalk account?
There is None, resetting password on Beta won't affect your account here.
As we know resetting passwords through secret question will suspend accounts in current forum
and are there any direct-indirect threats of ban from tempering with new version?
Secret question doesn't exist on the new forum, AFAIK. Only reset via email at first login, for extra security you should use different password.
If i'm correct it's not sync. I never tried posting using the Beta, don't know if it will affect here.
Didn't use new soft because of fear that accidental ban may happen.
Somebody, maybe experienced that already?
Ban?? Maybe you mean locked. I didn't saw anybody complained for accidental locked on the new forum.