The game recognizes it for sure, when I attack someone in the game with these perks the game recognizes it by showing me how the enemies are decapitated. It is true recognition by every standard. Regarding this not having an effect if I use another weapon, that makes perfect sense to me, a very strong football player is not by default a great weightlifter or a good javelin thrower since they all require completely different use of muscle strength and training to be accomplished in. No speed or agility? Yet again, I have descriptive traits that tells me that my character is agile and fast; "deft movement", "agile defender", "light foot", "dual flurry", "lightning reflexes" and all of it is reflected in the game.
We're talking physical, raw strength here. First of all, football players (American football, I should say) DO weightlift in order to become better football players. The muscles associated with the task of throwing a football can be exercised in weightlifting, which also means a football player is generally a better weightlifter than a non-football player. I don't expect the game to know the strength of my individual muscles, just my average, overall strength. A longswordsman can still use his strong muscles to fight with a claymore- except in Skyrim. Second, about the javelin throwing- we are still talking about basic strength. Skill has nothing to do with it. I'm not talking about fighting techniques differing from weapon to weapon. Doing a simple overhead slashing attack has nothing to do with skill, just strength. A stronger person can swing the weapon harder than a weaker person, thereby doing more damage. In this sense, strength should carry over to all melee skills as it has in the past, but this is not the case anymore.
And please, using descriptive traits doesn't reflect attributes as well as attributes did by themselves.
-Deft movement- I'll give this one to you. The bonus accurately portrays agility
-Agile defender- only increases light armor rating. Agility is about not being hit, it has nothing to do with absorbing damage.
-Light foot- I'll give this one to you as well. Not setting of pressure plates is an agility related skill.
-Dual flurry- I'll also give this to you. Attacking faster with weapons accurately portrays agility. However, this only applies to dual wielded weapons ONLY, and nothing else. The second you drop your second weapon, you are instantly less agile in game terms.
-Lightning reflexes- (quick reflexes, I assume) slow mo when blocking a power attack. Could accurately portray agility.
Yes, those perks with the exception of one can be used to show a character's agility, I admit (although dual flurry doesn't make much sense realistically).
But I must ask again- how can I increase my speed? How can I increase my jump height? The answer is that I can't. I could in Morrowind, I could in Oblivion, I can't in Skyrim.