I find it a bit odd that a developer's standpoint stresses RPG ruleset design rather than overall game development. Most of the unreasonable demands and unrealistic hopes for Skyrim features I see aren't feasible because of other development factors. Deciding how your sword attack vs. armour + variables works is really the easy part, when you consider that the animators have to make it move right; the artists have to make the sword, the guy swinging it, and the armour it's hitting; and the programmers have to make it happen. Older RPGs tend to have a lot more content (look at Daggerfall) because what takes so much time and manpower isn't RPG design, but the production of the art assets required to create a game with modern graphics.
I know very little about engine programming though, so I can't comment on that.
Interesting post, but I don't think it's as valuable as it's being vaunted as -- meaning no offense at all -- partly because you haven't given much insight into the full breadth of game development, and partly because the people who might learn from it probably won't read it.
One of the things people chime up again and again is how things are broken in previous installments of a game franchise. Since we're on a BGS forum, I'll use the spears and levitation arguments as an example.
If your athleticism was high enough in Morrowind, it was easy to back-peddle, forward-stab to get the most damage out of the weapon, coupled with the 'always use best hit' toggle in the menu. This means you would miss more often, but when you did hit you could practically one-hit an enemy. For some reason, gamesas thought it best to scrap this weapon entirely, most likely due to the fact it was probably difficult to get the enemy scripting to NOT always stab, or perhaps they couldn't get them TO stab enough with the addition of the new combat system in Oblivion. It was probably harder to try and fix the problem than scrap it, so they opted to scrap. I would also like to add, that during my 4 years playing MW, I rarely encountered an enemy using a spear, and when I did, I just used magic. Not to mention, a spear is longer than a sword, and you could easily just stand far enough away and never be hit by the enemy - but then that brings up the idea behind bows... this was combated by giving many NPCs magic or a bow of their own to ward off a ranged attacker...
As for levitation, there really isn't much of a way to fix the exploit people would use to 'win' the game. I'm sure they tried to use a form of levitation in Oblivion as well. However, much like I said above, it was probably difficult to get the NPC to act and react accordingly with the scripting system. I could easily see an NPC with a high amount of magicka stupidly deciding to keep casting the spell and go higher and higher into the sky, following the PC until they run out of magicka, only to fall to their death.... Or the same could be said if they followed you off a very high cliff...