[If you think they can't box, you probably haven't watched too much in the past few years. In the beginning it looked a lot like a bar room fight. Now, most all of the top guys train with boxers and kickboxers, along with several different martial arts.
Tank is from the early days, he is a nobody now. I wouldn't call him unskilled by any means but definately not up to par with the new generation of fighters.
I haven't watched that much UFC, you are correct. I have been watching a fair amount Pride fighting however. I find the guys in there are better skilled. I also watch K1.
You also mention that a top heavyweight won't last than 20 seconds in a No holds barred fight. That is claim that doesn't have that much merit. Granted, the chances are that once on the ground it is over. Yet it has to get there first. Yet again, the opponet has to withstand a non-boxing gloved hit by a trained top heavyweight fighter. Although the UFC guy has trained in Boxing, who is to say the Boxer won't learn some basic manuvers as far as ground tactics. My point being that it is not a done deal to say it would go one way or the other thats all. I like MMA fights very much. I watch them when I can. However I like boxing much better. I do belive that it is here to stay. UFC is small potatoes here in the USA. That is why most of them move (the fighters) on to Pride or K1. there is a lot more money in it overseas in Japan.
As far as Bruce Lee is concerned..... Where are results of him fighting in profesional competion. Sure he looked great in the movies and maybe great in sparring. To the best of my knowlege you can't really compare a movie star to real life fighters. For example, Van Damme was knocked out by his old body gaurd, Chuck Zito. Personaly I don't think at his small size, Bruce Lee would be able to knock many people out. No offense to fans of his, but he was a movie star. IMO
BUTTERBEAN!!??!! What a joke! I am drawing a blank of his name, but an old heavyweight (almonst 50) beat the crap out of him last year. LOL