Comparing Silva's weight to Fedor's weight doesnt' fly for me. He may be at 230 a week or two before the fight, but he cuts that weight over a good chunk of time. Basically, that means that he isn't cutting water weight for most of it.
It is kind of like a professional body builder. During the off season, many of them pudge up somewhat to allow their body to feed the muscles properly. Then, when competition comes around, they cut it all down. Obviously, that isn't all water weight.
Silva, IMO, probably weighs about 190ish after gaining back his hydration. Obviously that is just my speculation.
As to his weakness to shots, who was the last guy with great BJJ that he fought? The most recent with talent would probably be Lutter and Silva submitted him with style.
He doesn't have to worry about takedowns from his opponents because none of them are much of a threat to him on the ground. Instead, he can clinch, leaving himself open to takedowns, giving himself the opportunities to throw knees.
We'll see when he fights a guy with solid BJJ how willing he is to clinch and possibly give up the takedown.
I'm not saying you are wrong,(though I do think that either Anderson or Fedor are #1 p4p) I'm just giving you my 2 cents on the issues you brought up.