Rogue - "Boy, I would sure like to attack that squishy wizard who is fireballing my friends, and my fighter friend even provided a flank. Sadly, NON-MAGICALLY, this other fighter is somehow subverting my high intelligence and forcing me to attack him."
Yah, that make sense. I can do without the "holding aggro" mmo-concepts.
AoOs and fighters blocking off access to the squishy underbelly of their party is what I prefer. Animals, monsters with low int, etc will fight whoever is attacking them, in my campaign. Smarter opponents will attempt to act like they are smarter and will try and take out the healers and wizards.
Again, marks force nothing. That rogue can go attack the Wizard if he wants to. Of course the fighter can non-magically slice his legs out from under him, and if he hits you, well, you ain't goin nowhere.
There's nothing 'forced' about this. The rogue knows the risks. If he tries to go after the Wizard with the fighter attacking him, he runs the risk of getting his feet cut out from under him, and movement stopped, as well as it hurting a lot.
That, by the way, is one of the unique Fighter class features, known as
Combat Superiority. Literally, the fighter is the superior combatant to any other class in the entire game. When you are engaged with a fighter, he controls the flow of battle. Unless he misses, you cannot shift away from him.
Again, is this magical? Well, if you call everything that is "cool" in the game magic, then yes, it is magical. If your definition of magic is "if the effect is more interesting than hitting with a sword it is magic" then fighters can do magic. That's one possible definition of magic. In my opinion that's going to leave a lot of non-magical classes as basically second-class citizens in a weird wizard show.
If you are basing it on what people in the real world can do with real weapons, it can be hella difficult to get away from an angry guy who has trained his entire life to be the ultimate combat machine and has a big sword.
P.S. Your system boils down to 'fighters are less useful against the BBEG or his lieutenants.' So basically not only does Vancian magic mean that casters have powerful daily resources to blow in the BBEG fight, it means fighters will lose one of their roles in the party in a BBEG fight. Meaning that the BBEG fight is basically a race between the BBEG and the casters to see who goes down first, with the fighter lamely swinging his sword for some damage, I guess.
Not an inspired system, to say the least.