All magickal effects benefit from Weakness to Magicka. The Weakness affects the NEXT spell casting.

if that's the case, not sure what's the issue here with my enchanted bow lol

You're not sure, because you're not paying attention to the answers you're getting.

This is the bow you described: "Damage Health 15pts for 1 second, Drain health 30pts for 1 second and Weakness to magick 100% for 1 second."

The "Weakness to Magic" part of that enchantment is 100% worthless, and it's just costing you magical points that could have been put into one of the other effects.

It's worthless, because Weakness to Magic needs to be in effect BEFORE the other effects. And not in the same spell. It needs to be cast first, in a separate spell (or in a previous casting of the same spell.)

It's also worthless, because it's only one second long, so it won't last long enough for another spell to be cast to use it.

This is all true but I would point out that the weakness to magic component would not be worthless if the exact same enchantment were placed on a dagger. Weakness to magic enchanted on a weapon will stack with subsequent hits from the same weapon and a dagger is quick enough to get multiple hits in one second.

True, but it's a bow, so it's worthless.

The point that Stealthblade is missing is the fundamental one: The Weakness to Magic never applies to the magic effects on the same hit; it applies to the next hit.

And yet, it's doing precisely what I wanted it to; so again i'm not seeing the big issue here. Whether or not it's actually doing something, which i feel it is, isn't really the point. The point is whether the bow is doing the damage I want to get OHK for that time period. While armored enemies or flame atronach are not dying in 1 shot, it really makes little difference because that dagger i created hasn't done that either to those same enemies, it takes the same amount of hits to kill them with that dagger as the bow.

The "issue" is knowing how to use the Weakness effects in spellmaking and enchanting. We are trying to help.

Your bow is working for you because the damage effects in it are big enough to produce the results you're seeing, without the Weakness part of it. The Weakness part of the enchantment is not contributing to that result. It's not important for this bow, at the present time, but it may be important to you at some later time.

The Spells-In-Hand mechanic was only implemented into Skyrim. Personally, I like the Oblivion set up way more. Especially the Hot-Key over the Favorite Menu. Easier access to everything at the tap of a button. Attacking, Spells, and Blocking, a Torch when sheathed. It's nice.

As for gear, I usually wear a robe, maybe a hood. For the rest, Heavy or Light Armor depending on my character/class.

i seriously don't think the "Damage Health 15pts for 1 second, Drain health 30pts for 1 second " is doing anything significant on it's own. I'll create another bow with those same two things and compare the difference later on.

glargg is correct, the weakness effect doesn′t do anything here.