The canon is vague here. The Warden swords seem to operate on secret rules that aren't actually written in the books.
For example, they can be used in two different ways. And their uses are shared between those ways. There's nothing in the books that lets you make items like that.
So yeah, there seem to be secret rules which can only be discovered through inference. Makes me feel like I'm studying a religious text.
Well, I should probably point out that this is a houserule. I believe by RAW, you can't buy Refinement without having one of the Spellcasting abilities. But it makes enough sense to me, that I allow it, as long as people aren't abusing it.
Refinement has no Musts, actually. But all of the Templates which get it have spellcasting as a Must, so...it's ambiguous.
And whether you can take up other people's items at full strength is also unclear. The Warden sword implies that you can, but I'm inclined to ignore that implication for balance reasons.
Spending Refresh on the ability to craft increases the value of every Refresh point you spend on item slots. Sharing that benefit with your whole team can make for some monstrously powerful groups.
I expect toturi can demonstrate, though he probably wouldn't have a problem with the demonstrated group. If I recall correctly the guy plays at a very high level of optimization.