Mayweather has already started to decline. Khan is on a steep upward curve of improvement. Within 2 years Khan will beat anyone lacking the power to knock him out. Does Mayweather have the power to stop Khan? Yes. But I think Khan could survive against him. Honestly, I don't think it is outrageous to think that Khan will have the beating of Mayweather within 2 years.
Khan can't do anything with Floyd right now. I do think Floyd has been on the decline over the years. He was better physically from 130-140 than his years at 147...especially at this point. Now at 33 years old and not getting any younger, eventually, his attributes being on the slow decline "can" make him at a disadvantage with someone with speed, agility, work-rate, etc...as he continues on. So If Khan waits long enough and Floyd keeps fighting a lot longer...who knows.
It's the two punch combinations that Mayweather likes to do now that bother me as well. It's highly effective but if you were given a choice...master of the two punch or master of the 3+ combo...nobody is picking 2. Before, back in his 20's, specifically the lower weight classes, he could burst out with a 3-6 combo and light up a fighter. He was also better at attacking. Maybe he is worried at this point that if he goes more than two, say a 3 hit combo, he could get caught while trying to throw that 3rd. Not saying he never does it but compared to before, it's not common. His lead-left-hook is slower for sure. Go back to the Diego fight for example and that hook was incredibly fast. I just don't get why some people think even the Great fighters won't fade eventually or haven't been fading. Even Roy Jones Jr, the most gifted athlete I've ever seen box, declined in his 30's...way before he even got to Ruiz and had to come back down in weight...he was on the decline. His best was in his 20's and slowly decline after a point in his early 30's.
He has to get pass Madaina, Peterson, Bradley, Alexander all Beats Khan and you wont see him in the ring with none of them