AWKWARD ZOMBIE

It's weight that influences your noise so yes.

I have been a Sneak character since level 1. Sneak has been useful through all my levels, even low ones. (Currently level 33 with 84 in Sneak.)

Higher skill level makes you harder to detect but simple enemies will still have trouble even at lower skill ranks. Plus, there are those perks that give you +20% to your Sneak; you can get one, then another at rank 20, and another at 40. Unless you're playing on higher difficulties, that's all you'll ever need.

Go with Archery, at least at first, since bows are still useful weapons when not in Sneak (compared to daggers, at least until x15 perk). Also, if you use a bow, you can snipe people from far away, so if there's a group, you have a chance to pick off multiple targets before they actually find you.

Also, something people tend to forget/not mention, noise is affected not just by the weight of the armor (though that is most of it) but also the speed at which you move and the lighting in the area. If you move at a craaaaaaawwl then you're harder to hear, and if you sit in a shadow then you're harder to find. I actually walked directly into a bandit (face into his stomach and everything) because I didn't see him, but he didn't see me either due to my low speed and the cover of night. I knifed him right in the gut. My Sneak was only in the 50s at the time and I only had one Sneaking perk, just to clarify.

tldr; Sneak is good all around. Though I'm playing an easier difficulty, so maybe there are circumstances I'm missing.

Just crouch everywhere and you won't even have to actively try to raise your sneak. Seriously. It's the first thing I got to 100...on my mage.

Also try to actually hide. Don't just go in the corner of the straight hallway, go int the little alcove behind the flower pot, or behind where the door opens to. You can get pretty far away from the place of your crime through sneaking. The place where the arrow came from will be the first they check so get as far away from there as possible.

All this talk of people who have overpowered their characters to hell and back in Skyrim reminds me of how back in Oblivion, all you needed to do to be overpowered as hell was be a sneak mage.
Go to that one armor store in the Imperial City and autowalk sneak into the corner at the top of the stairs until you're level 100. Then just go make custom spells at their very weakest on yourself over and over until you have level 100 in every possible school of magic. Sneak everywhere and cast incredibly powerful electricity at everything.
Also 100% chameleon armor.

MY Skyrim character is way less powerful, sadly. Then again, I'm only level 18.

Reminds me of this:

Pretty much. Overleveling is really simple to do in Oblivion though, with its really, really shitty leveling system. Just look at Charlie Manhuge.

So are you guys familiar with this theory?

I thought the whole idea of CHIM was that it's supposed to explain how the player character works?

Apparently it was pieced together into a big metaphysical theory called the Walking Ways by very dedicated players who researched the lore and read every single in-game book.

No that was fan theory. The player character is sort of explained as the prophecised hero by the Elder Scrolls, destined to mysteriously and namelessly disappear after fulfilling the prophecy.

Wasn't there a few lines in a book though that sound very similar to someone reloading a savestate after dying?

I only remember the mage who turns invisible after hunting vampires to cheat her friends out of their bounty, and the guy who learns underwater breathing and is found drowned with two potions of water-breathing in his hands because he didn't know.

Hm... it only now occurs to me that I've hardly dabbled into magic at all, only really for transmutation. What's a good path of magical skills to maintain cash, mana, and power?

In Skyrim? See the previous posts.

Alchemy is always good for huge boosts in cash. Just enchant your stuff with magicka regen stuff and you'll never, ever, ever run out of mana.