Big Boss was the most skilled fighter of anyone in the MGS series, but that looks about right for a general 'strength' ranking. Raiden's cybernetic enhancements are obviously way ahead of the rest.
As for most of the MGS2 questions, the thing about Metal Gear is that you have to take it in stride. The series was never planned out in advance, so new things were added, and changed, to make room for the ever evolving narrative, which is why some specific details from MGS1 or MGS2 may not hold up by MGS4 or Peace Walker. The more games that get added to the existing storyline, the more problems are going to crop up, just because they have to be able to tell the story they want to today even if it means sacrificing the consistency from what they said ten years ago. Leon did a good job of getting most of them, though!
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"When I was a young man, I had liberty, but I did not see it. I had time, but I did not know it."