I think you are wrong. Not about who would win, but WHY. Understand, this is your best video yet imo, and I can tell you did your research, but ultimately you are ignoring a few key facts. First, you totally neglected to mention that not only can caedus blatantly IGNORE absolute agony, he can FEED on it to improve every aspect of his martial abilities, making him like your typical "reaver" class fighter found in many fantasy games. In other words, the more you hurt him, the more power he gains, and gains EXPONENTIALLY. Leaving out this fact is not doing his character justice. In addition, you failed to really touch on just how vast his array of force abilities are, and the casual ease with which he can use all of them.
Frankly, I think that in terms of power, speed, ability, etc. when ALL is considered, Caedus FAR outclasses vader in all areas, with the exception of raw lightsaber skill. But I still think Caedus would lose. Why? Its simple, and has little to do with skills or powers or strength. It is entirely esoteric: MOTIVATION. What DRIVES them and fuels their power in combat.
Both are Sith lords, relying on emotion to fuel their force abilities. But the key difference here is that Caedus is not primarily driven by hate (although he is VERY prone to outbursts of anger). He is, instead, fueled by his love for his daughter, Allana. Even his assassination of Mara was done out of love (albeit a twisted, selfish love). He wants to unite the galaxy and create an era of total, perfect peace for his daughter to grow up in. He wants it SO badly, he will gladly force it to happen with an iron fist. While he does rely on hate to fuel his power from time to time, it is almost always circumstantial and entirely in the moment, and when that moment has passed he resumes his normal mindset. The key thing to note here is that HATE is by FAR the most powerfull "booster" if you will, of darkside ability.
In contrast, Vader is driven, in his current state, by similar goals, desiring power to rule the galaxy and thereby force peace on it, but not for himself or anyone else, but because its all that is left to him. He is driven by all emotions, but primarily by hate. Hate fills every inch of his being, down to the the depths of his soul and every fiber of his being, and it fills him literally every waking moment. He hates his master for trapping him in his useless mechanical body. He hates his mechanical body. He hates the doctors and medical droids that built it for him. He hates Obi Wan for his defeat and for abandoning him on the shores of mustafar, leaving him to die alone in abject agony. He hates everyone and everything. But all this is, like with caedus, is circumstantial. A moments distraction will divert his thoughts and hate away from those things. BUT, what makes him so full of hate, all the time, is the fact that he HATES HIMSELF more than anything else, and he can NEVER escape that.
In addition, his failures have left him utterly humiliated, and have humbled him. He has lost all of the self assured cockiness he had as Anakin, and as a result is more deliberate and wise. Whereas Caedus saved the galaxy from the Yuzhan Vong, is a powerful force wielder from a powerful lineage, trained in a vast array of arts after a decade of wandering the galaxy, and has never once suffered a defeat or failure on the scale of vader's failings. He is cocky and arrogant beyond measure, and as a sith lord is little more than a spoiled brat who feels entitled, and therefore to blind to see why he is, ultimately, weaker than any other force user.
THAT, evan, is why vader would utterly crush Caedus, despite his vast power.