No, but they've all played in observed games. I think the Klitschkos are supposed to be better than Lewis, but none of them were very interesting.
I'm guessing it took Valuev a good 1-2 years to complete his studies to attain those degrees? ...I believe you're missing a few as well.
I used to think it was bull****, not because they had to do a thesis, which their thesis' were on their experiences/training as a youth, that is an easy topic. Its all the classwork required, in the US it is 60 hours which is 3-4 years and most of the time students teach classes or work for the professors so that takes a long time. Somehow though I do remember reading somewhere they did take all the classes. If it is a really easy school and already in an easy field then its believable they could do it in the early 90s while competing. I mean most pro NFL players have degrees and it was always some stupid communications **** that they would have no problem to do while they are traveling playing in the NCAA.