So I'm done the mage college/thieves guild/dark brotherhood quest lines. I'm also about 3-5 quests away from completeing the main quest line and am level 38. After 75 hours in I decided to get Draedic armor+weapons.

My first question is, will making my armor/weapons legendary break the game? I'm talking about improving my Daedric bow to about 100+ damage. Also, if I decide to just improve my daedric items to legendary with bad stats, can I improve them again or will I need a new set of daedric?

Second question is will creating iron daggers with the banish enchantment on it ruin the game? For the unaware, you can put a banish enchantment on iron daggers so they will have a value of 1800-2100 [I can sell it to warmaidens for about 900 coins]. I plan on making enough daggers for 30 to 50 enchanting, so I estimate I will have 100ish daggers and if I sell them I will have +90,000 coins. I currently have 35,000.

In short, how badly will doing the above detract from the game experience? Would doing this be game breaking?

Only you can truly answer that, because it is a single player game, our definitions of "break" and "ruin" are completely different.

Depends, if you don't mind being overpowered and being like an actual Hero, decimating everything in your way, then no, it will not.

It really all depends on what YOU think is game breaking. I have never personally thought that getting a lot of gold was game breaking, since after a while it really isn't necessary for anything. As far as improving an item again after you've reached legendary on it, I believe you can still improve them without having to create a new set. As for how powerful your armor and weapons are I dont really have an opinion on that.

You have to find your happy medium; some people like frustration and getting their asses handed to them, some people like a moderate challenge and some people enjoy handing out building kicks and explosions like they're hotcakes. Which do you prefer?

Okay....

I'm at level 58, I've put in 450+ hours on one character...I've only recently maximised my smithing and enchanting skills to 100, and haven't power levelled anything, apart from a couple of skill spurts to up-level. My favoured weapon is a hand-axe, which with upgrades and skill factors comes in at around 164 damage points...my armour is plate steel which is now above the armour cap through upgrades and skill enhancements. I've only just finished the main quest. My character IS the stuff of legends...the best fighter/warrior in Skyrim, a skilled smith and enchanter, and a general all-round good guy, but people don't mess with him because he's very persuasive and can be intimidating. Generals and Jarls listen to what he has to say. Is being a legendary, tough son-of-a-hargraven ruining my game, or does it make me the stuff of legends standing beside Ysgrammar and the Nord heroes of old?

You can only answer your question, but are you playing to 'beat' the game, or are you playing a role?

I don't think money breaks the game because there isn't much to do with it.

IMO it's not so much upgrading weapon damage that's the problem, more than anything it's upgrading defense, especially magic resistance. Or just generally using the double enchantment perk to layer lots of enchantments. Basically at some point you have to gimp yourself until you start getting killed at a fun rate. But the main thing I have done is put elemental damage resistance stuff back in the cupboard.

I've found that the stronger your character gets. The more boring the game gets.

You can still upgrade equipment that is 'Legendary' if you equip Fortify Smithing gear. No need to make new stuff, unless you want different / stronger enchantments on them, then you have to make new gear.