So I'm trying to make the best possible weapons and armor and I have a few questions.

1. If your smithing, alchemy, and enchanting is 100 does adding say a +30% smithing potion increase how much you can improve your sword? If so is there a cap? like having boots, greaves, gauntlets, and chestplace give +25% and potions and such what is the limit? if you have +20000 smithing will it be better than +500 smithing?

2. how do i make the best armor, like, do i increase my alchemy with an alchemy potion, then increase smithing, then enchating?

3. what is the most effective possible potion you can have to increase those 3 individual traits?

4. what weapons and armor set is the most powerful in the game? I have practically unlimited resources in skyrim i just want be sure to know the formula to making the best armor/weapons.

There's a cap of +32% boost with enchantments and potions to boost your skills. These can be taken together to get a +64% boost to the skill, I think. Diminishing returns occur on about +28% boosts (meaning more is required for the same amount of boost.) You can do more, but it requires cheats/exploits.

But remember, for armor there's an effective cap at around 562. Any more won't do much unless you encounter the handful of game mechanics that flat-out ignore a certain amount of armor rating. You can (if you work for it) create a suit of steel armor that meets or exceeds this cap.

Best armor/weapons is Daedric. Dragonscale if you prefer light armor.

A general formula to create your gear is to use both enchanting and alchemy until you can make the +32% fortify boosts, then smith the equipment, then enchant it.

The higher you get your skill past 100, the better your gear is. However, I have some news for you. The armor rating is capped at something like 560-580, anything past that doesn't matter. Also, for weapon damage, I wouldn't really see it as necessary to past 175 damage. Your weapons are at godlike levels at 175 damage, even on master.