To avoid the multi quoting I'll focus on one point.
If you are never meant to hit 100 blacksmithing because you should be playing casually why make that the requirement for Dragon armour? Something that I would assume a lot of people were looking forward to wearing once they find out about it.
Once you reach that point why wouldn't you use the best gear available to you? Sure, you can make it a challenge for yourself. Where do you stop? Is ebony too much? Is dwarven? Each time I win a fight too handily should I downgrade my gear? It should be expected that Bethesda tests things like that before they put out their product. There is no point whether you're level 16 or 60 in which having this gear doesn't break some of the fun factor, immersion, gameplay or whatever you want to call it by making encounters too easy.
Why is it too much for me to expect to be able to wear dragon armour without micro managing my character's gear?
I never said that? I even pointed out that the whole point is that eventually, you will reach maximum skill level, and that you can do so for every skill. And that's the whole point of progression, that you slowly grow from a weak, puny individual into a dragon-slaying badass of which the greatest of songs and odes are written, and every time you draw your weapon, somewhere someone busts out a metal solo and the horns are thrown high in the air.
You have the choice to use what you want. Just like you have the choice to use whatever skills you want. You don't have to use any of the skills that you don't want to. That's what this game and the whole series is about: Your choice. You can do whatever you want within the game's limitations that Bethesda set forth.
You don't have to get the highest level armor right away. You don't have to get the most powerful weapon right away. You don't even need to have the most powerful stuff to succeed well and have fun. Get off that old-school JRPG mentality where there's supposed to be an "ultimate" set of armor and weapons and an "ultimate" boss enemy outside of the story that provides the ultimate challenge.
There was a thread I want to find that's a perfect example of someone understanding this, some guy who wanted to play a character he'd called a "business lizard." His intention was to be an Argonian merchant type of character who didn't adventure, but instead traded and sold goods. He wasn't going to be about finishing quests and smithing uber gear, he was about finding things he could sell so as to build his own little merchant empire, and when he had to go to dungeons, he would hire mercenaries to do the fighting for him. That's perfectly a demonstration of the spirit of TES, the fact that nothing truly limited him from playing that kind of character, and he wouldn't be prevented because the balance scaling was so off that he was required to only use the best possible gear of the best possible quality.
You have the choice of what you want to do, nothing's limiting you from that but your own self. And yes, some choices have their consequences, like the choice of grinding Smithing early on in order to get access to smithing Dragon Armor by the time you're level 15 will mean that you've effectively negated the challenge of lower level enemies right off because you decided you had to have access to the top-tier gear. But that was your choice to make, while being smart enough at the same time to realize the consequences of your choice. You don't have to get that armor, but you can choose to, if you want.