Role-playing by its very nature is the concept that a player has the freedom to make choices about what their character does and does not do. It's great that you decided for your character he would be ignorant of enchanting. How is it any less valid for a player to decide that, having achieved everything you did, he would explore the enchanting arts?... which everyone in the world know exist because there are enchanting tables all over the place.
What you are describing, in trying to construct a way in which players should restrict themselves in order to maintain a challenge, is in fact the EXACT OPPOSITE of roleplaying. Weighing abilities based strictly on their game mechanics, you propose various reasons players should not choose such abilities, thereby restricting the ability to roleplay.
Providing a friendly list of abilities that you consider broken even on "Master" difficulty beyond a certain level is one thing, but to accuse players of being at fault for failing to "roleplay" because they have stumbled across a build too powerful even for Master difficulty is... frankly ludicrous.
Oh, believe me. I don't restrict myself of nothing. My Warrior is even trained in Speechcraft and Lockpicking (although with no perks in any of them), just because I use both things a lot. But I couldn't care less if my stuff is enchanted or not, or if I wear the most powerful armor/weapons or not. In fact, the only reason why I wield 2 daedric swrods is because I love their appareance. As it's the reason why I wear Leather armor. And that's part of roleplaying. I am what
I want to be, and I wear
what I want to wear.
And on the other side, yes, roleplaying is also about restricting yourself, because it's incredibly improbable that a char can be Arch-Mage, the Companions' Head, the favorite of Nocturnal and the Night Mother, the savior of Skyrim and an accomplished smith, enchanter, conjurer, blademaster (1h and 2h), (...), mage-thief-warrior altogether. You can't master everything in life, neither you can't be the head of everything. It's a kids-like attitude even to try to achieve that, in my opinion.
Of course, you're free to try it. But then don't complaint when you don't roleplay on a RPG and things become too easy or uninteresting. Because it'll happen to you with any other game or sport in life...each and every one of them has it's rules. Break them, and it'll also become boring.
All characters have at least a rudimentary enchanting skill, and all it takes to improve it is to walk up to a table, put an enchanted object on it and press the button labelled "Disenchant" and presto; you can enchant/disenchant and you even gained knowledge by doing this menial task. In order to not being able to do this, you have to self-impose restrictions on yourself to such an extent that you're basically an illiterate fool. Sure, if you want to role-play such a character, all the power to you, but I'm not going to do that.
Same as above. If you don't know how to roleplay, it's your problem. Not mine. After all, at the end of the day I'm the one who has had 130 hours with my char and it's still having fun with him.