Is there any doubt that Brandon Tate would've contributed more as a Kick Returner and 3rd/4th WR than what we have now? (Our returners have been struggling to make it back to the 20 yard line this year)
Maybe, but field possition isn't a big problem for the Patriots because the offense can take on most of this league's teams. And the team has good punt returners.
Is there any doubt that Darius Butler would've contributed more as a 3rd/4th CB than what we have now?
No, not really. More of the same. Only more expensive. This, however, is one of BB's mistakes in believing he's the Warren Buffett of NFL Drafts: he was selected with the GB's 2nd-round pick they got, in part, for exchanging their 1st-round pick (26th, with which the Packers drafted Clay Matthews), which in turn was the 1st-round pick the Ravens traded them for their original 1st-rounder (23rd, used on Oher), letting Miami take Vontae Davis with the 25th. There the Patriots lost the chance of picking a good pass-rusher or a good cornerback.
Both Davis and Butler came in with red flags because of their personality and work ethics, but Davis had the raw talent and size, while Butler was also critizised because he was short and hadn't played great competition, having played for UConn.
Is there any doubt that Leigh Bodden would've contributed more as a 3rd/4th CB than what we have now?
Perhaps, but he wasn't exactly having a great year neither, and also was more expensive than the players we have now at that possition.
Last but not least, Is there any doubt that Randy Moss would've contributed more than Ocho Cinco has?
No, Moss was a slouch. OC is a slouch as well, I don't know why BB picked him up other than being friends with him. The truth is Moss excelled at the long routes, seams, 9s, etc., had lost a step there but he could still be dangerous. The problems is that Brady isn't very good at the long passes, so he would go on to be wasted. And when he isn't a feature WR, he loses interest and plays poorly.
I think the major problem comes from BB thinking he can break the bank with his adquisitions, both in the draft and FA. I think the draft blunders have been thoroughly discussed here and everywhere, but no the FA mistakes. Letting Merriweather go just a few days before the start of the season was a huge brain-fart. He may not have been the exemplary safety, but he was nontheless quite a capable safety. The Pats didn't have a good or average safety other than him and maybe Chung (who is undersized and hadn't had so much experience as a starter there). Basically, he let the team without reliable safeties, and that opened up a whole new level of problems for the secondary, aside from having no help from the LBs. Not picking up other free agents with better acolades than these scout-team rejects they have is a big problem, because they don't have the good, savvy veterans to help the young, and you can't rely on the young to pick up the NFL so quickly. So it becomes a sort of catch-22 that spirals down to where they are now.
In 2008, could have picked up Gibril Wilson, Erik Coleman, trade for Leonhard.
In 2009, Sean Jones, Wilson again, Darren Sharper, Jim Leonhard for free, trade for Dawan Laundry.
In 2010, Atogwe, Antrel Rolle, Ryan Clark...
There's a lot of cap space that was used for a lot of washed-up players given a last chance by BB: Fred Taylor, Torry Holt, Joey Galloway, Haynesworth, Ocho Cinco...
Time to behave like a normal NFL franchise, if you ask me. Make the sensible decision, not the maverick one.