I really like the tempest changes. They open up a lot of build options and there is still incentive to go pure.
I'd consider swapping core 3 and core 6 so that dex builds can get dex to damage earlier without the DWS tree.
This makes it easier for a dex based build to get their dex to damage earlier (and makes it consistent with assassins, acrobats, and ninjas getting it at their 3 core).
That makes the 10% offhand harder to get (consistent with moving the 2nd bonus from 12 to 18). This also nerfs the paladin 15/ranger 5 by 10% of an attack per swing bringing it more in line with a pure ranger in DPS.