1) Does Firiniel's End have a unique our rare "Slow" enchantment as the wiki would imply, or is it just the standard slow effect you get off all cold enchantments?

2] Assuming it is a unique enchantment (outside of Alchemy] what school of magic [if any] needs to be fortified in order to get zero charge cost?

I just looked it up and I'm guessing it's an Alchemy-type debuff that's permanently applied to a weapon that cannot be replicated with Enchanting. I believe there is another bow that has a 'permanent' Poison affect (Daedric Artifact maybe) that cannot be made/enchanted by a player.

Very nice, so it is a unique enchantment then? Interesting. I hope it can be improved with arcane blacksmith and elven enchanting, if so I have a new primary weapon! Wonder what magic school the slow effect is governed by though...

Destruction.

That is a fantastic weapon. I have vowed to stay away from enchanting and, to an extent, smithing, for future characters, so that is a great bow to have.

Meh. I have a ridiculous excess of slow potions in my inventory. I usually sell them.

So with fortify destruction at 100% I shouldn't have to recharge? Noice. Anyone know if any other weapons share this enchantment?

It's a http://www.uesp.net/wiki/Skyrim:Frost_Damage.

That is what I was afraid of. Ah well. I wish you could isolate the slow effect and tweek the magnitude. Also slow runes would be good for archers.

Are you sure?
Slow is listed separately:
http://elderscrolls.wikia.com/wiki/Firiniel%27s_End

Firiniel's End has the same stats and enchantment as an Elven Bow of Freezing, except the unique weapon has fewer charges and is worth more than the generic weapon. In particular, generic frost-enchanted weapons include both a frost damage effect and a slow effect. The only way to get frost damage without slowness is with The Pale Blade, and you can't learn that enchantment.