4 +25% smithing armor pieces obtained from 4 grand soul gems and 100 enchanting.

The potion is something you can buy in shops, that go from +20 to +50% fortify.

Ah got ya. Well I definitely can't do that atm as im not aiming to max out my enchantment.

Where is this karlha's bow... I'd imagine you should get it from her, but I've found no evidence it even exists.

Anyway, I know the lighter the bow the faster the attacks, but its never made or broke me... Especially since I have the draw 30% faster perk.

I think that lighter bows are better for "in the Frey" battling, and heavier higher output bows are better for sneak attacks. So depending on what type of archer you are will determine your bow makeup.

A bow for someone who doesn't sneak around or doesn't have a high sneak may use lighter bow enchanted with paralyze. Because paralyze is iffy if it works because your using a low damage fast out put you would most Likly have more chances to land an effective paralyze shot.

Someone who relies heavily on sneak may have a bow that may be heavy, but it's damage output on a single shot is high. Thus more of a chance to land one hit kills while sneaking around. So having paralyze on this characters bow may be an entire waste, but having perhaps a damaging effect may be more benifical here.

So it's totally dependent on the character build and strategy used. DPS should not be the reason your picking your bow. You need to first find out if you need to shoot a lot and fast or shoot a little but hard. Then choose the appropriate bow.

I like the Bound Bow.

That bow would work better if you just used shock together with weakness to magic 100 and weakness to shock 100. Boost the drain to 100 and you are set to go.
This is a weapon who is very overpowered as just the drain health effect will kill anything with less than 200 health after two shots.
Weakness is the low base damage and few charges, easy to do 500 hp sneak attacks in Skyrim with an unenhanced bow.

In fact the magical damage is so low it's better to focus on other effects like the slow effect of cold or paralyze.