None of the proposed "refund" scenarios (yours included) help out the classes most harmed by this change; melee/ranged hybrids (xbow excluded; they basically get a free respec). The refund scenario in the OP allows certain wholesale class changes (such as 2h->archer or polearm->xbow+1h), while excluding much more minor class changes (melee primary+archer secondary->pure melee).
If hybrid xbowmen are allowed to dump their xbow wpf, why can't hybrid archers dump their PD and hybrid throwers dump their PT?
I say have the refund script do the following: If a player's wpf in any melee proficiency is greater than their wpf in archery or throwing, refund their skill points in PD/PT. Otherwise you are going to end up with a lot of melee+ranged hybrids that no longer have the available wpp to support their build.
Cause, that's basically more or less full scale respec. My change(and his) are to allow people who put to much, one way or the other, to actually get BACK their skills. What you're asking for is, essentially a repec out of Class 1 into class 2.
By making it 18/18 or some combination, it's a not a full respec, and your choice to this point still MATTER, but it won't be a you get screwed over from a change. And if you're an archer NOW, the likelihood of you switching is extremely low. Also, melee will still have their skills above whatever scheme we talk about. Every class is effect, not just archers, so stop whining.
Also: melee ranged hybrid will still be just fine(just you'd have something like a 100/80 split or 97/97 split. Infact, this update WOULD have screwed thrower hybrids over if they didn't change PT from 13 to 11. In fact, I'll have +20 more wpf for throwing lances even though I'd LOSE 3 points.
They are also nerfing Archer accuracy with this patch to, to compensate for the wpf change and increase in accuracy that it'll bring.