Wasn't going to entirely stick to non-combat, but was planning on getting high level just via non-combat means as a sort of experiment. Game apparently doesn't care for this idea, and sends hired thugs and some wizard who wants a wizard duel at me. There's just no way of escaping combat even by sticking to the cities.

I'm level 12 with no combat skills or perks whatsoever other than LUCKILY some illusion just from casting muffle. I was able to calm them, hide, and frenzy them into getting killed by guards.

Had I not had illusion though I'd have been completely screwed - the wizard guy would two shot me with lightning spells and in fact if he hadn't gotten close to declare his duel I'd probably have been dead since trying to aim calm(why I have to aim a mind affecting spell like it's a destruction bolt spell I don't know) on magic using NPCs which move like they're gliding on ice or something is difficult enough that I'd have probably taken two hits before I could hit him. Pretty much everyone knows NPC magic damage is completely messed up until you get a lot of resist, but still, pretty lame.

There are no dialogue options for the hired thugs, and both dialogue options for the duel challenger lead to combat - no way to use persuasion or anything.
This is kind of a response to many posters who've said things like "you shouldn't expect a non-combat character to do well in combat" when discussing level scaling. I find it a poor argument regardless, but even a non-combat character who intentionally tries to avoid all combat will have it delivered to them.

I'm trying my best to remain a pacifist with my new character, but it's extraordinarily difficult. The problem is having enough skill and magicka to cast strong illusion spells without the enemies being too high of a level to cast on...or something like that.

Just think as this as like real life, not all thugs will leave you alone if you are charming lol.

I am currently playing a Mage who does not directly deal damage, he has no weapons and does not cast destruction spells.

He uses Muffle and invisibility then 'fury' or 'calm' to bypass enemies, and if stuck he will call upon a atronarch to help in his escape from direct combat or to clear a dungeon.

so you are not completing any of the quests that require you to fight (which is a good many of them)? just training in illusion, alteration, and the craft skils? How long have you had to put into the characters before you actually got to level 12?

Illusion is a must if you want to avoid combat.... It's also quite humorous at times.

Primary skills for a fast-talking thief would be sneak, pick pocket, locksmithing & speech.

Sneak has x3 bow and x15 dagger damage for sneak attacks... your only real method of personally killing.

IMO: Assassinations aren't really combat.... but you can even forgo that if you want to be a pure pacifist.

I've started a Khajiit who will be my Skyrim Criminal Especial.... he's going to rob the entire province blind. I'm also going to do some dark brotherhood probably just since there really isn't a WHOLE lot I can do besides thieves guild/DB.

For the time being, I've been using pickpocket, alchemy, lockpicking and was only really using illusion for muffle when breaking into houses but I'd been casting it as I travelled just to raise illusion. I haven't spent a lot of time on the character but you level pretty fast in the beginning.

If I were going to try this for pure RP reasons, I would just go grind grind grind illusion up to about 75 before I did anything else.

I'm going to probably end up getting Illusion, Alchemy, Enchant, Smithing, Pickpocket up really high, then making humanoid enemies fistfight eachother in their loincloths. Or maybe have them fistfight dremora lords in loincloths, picking up conjuration is probably a good idea. Going to boost pickpocket via enchant or potions instead of wasting 4 extra perks in the pickpocket tree, this is kind of my "messing around" character so I don't care if I make him absurdly overpowered abusing the crafting skills.

If Conjuration counts as non-combat then you have many opportunities to cause mayhem, especially once you learn "Mayhem" Sit up on a ledge invisible and watch 20 Forsworn fighting each other and two Dremora, that is always good for a laugh. Use the Ritual Stone power half way through.