Sorry Mr. Bigglesworth, I have not encountered any of those bugs and I'm definitely well past the tutorial areas. HAVING a bug is not the same as EXPERIENCING a bug. Just because the game files on my hard drive contain code with bugs, it does not follow that I am experiencing those bugs.
Thing is, most of the bugs you mention don't affect more than a small percentage of players. That's not at all the same thing as saying other people have "bug-free" versions of the game. But consider...
The majority of people who play Skyrim will almost certainly never see a dual-wielding werewolf issue, for the simple reason that most people probably don't ever become a dual-wielding werewolf. Many people won't do that quest line at all. Others will see werewolfism as a Bad Thing and reload the game as soon as they contract it, or immediately look for a way to get 'cured'. And of the ones who do the quests AND continue playing as a werewolf, most won't be dual-wielding.
The majority of people who play Skyrim will never see a heavy armor + unarmed bug, again because most people simply won't ever use that particular combination or armor and (no) weapon.
I'm well over 100 hours in, and I've never seen any of those bugs. But I also have not ONCE swung a 2H weapon or worn a piece of heavy armor, or tried dual-wielding as a werewolf. Maybe I'm just getting lucky and my builds just happen to be the only bug-free ones.
As for quests -- I tend to roam around freely exploring and taking quests in more or less random order, and I've never read a guide. So far, I have not had any problems with quests being broken, or with quest items not disappearing, or anything else. Keeping my fingers crossed and hoping this continues.

Oh, and I've had my tail kicked by dragon priests who very definitely didn't lock up and do nothing.

We are all playing the same game here.
Everybody has the same quests glitching out under certain circumstances.
Everybody has Conjuration summons failing with spell absorption.
Everybody has their Heavy Armor +Unarmed Damage perk broken.
Everybody has the dual wielding Werewolf bug.
Everybody has Dragon Priests locking up and doing nothing.
Everybody has dead Khajiits still moving their tails.
If you've played Skyrim and honestly claim to have not encountered any bugs they you are probably not even out of the tutorial area.