This has been stated a lot of times on HN, but anyways :)
1. I think you are mixing deals
2. GOOG accepting MS offer would have been dumb. Google wanted the patents to avoid lawsuits from MS-Apple. Teaming up with them would have meant that these patents are useless against them (I assume that Apple/MS would not have said - okay we team up for now, but you can sue us using these patents later).
3. I am not sure, but a lot of people have quoted that Google has been vocal about the stupidity of patent system even before these deals. Also if I am involved in a deal, I will never speak of it (or the stupidity of it) in public. That again, would be a dumb move. So yes, Google's statement should have arrived after they lost the deal. Also, AFAIK they said that the patents might be useless to them technically, but they needed them for litigation wars.
4. Using Pi*1bil as a bid, is no different than 4bil (Other than the magnitude of course). Not to logical people at least. Yes, lawyers who are not aware of the digits of Pi or shareholders who bought shares of the company X because the saw it climbing a month ago, would feel that, but that's dumb stereotyping of numbers - I would say. In fact, 3.14Bil sounds a lot more cultural and sophisticated to me than 3.1 or 4. But that's probably the geek in me.
5. Yes they paid 3 times more. But they also got 3 times the patents (and these are not licensed to MS!) + 1x times patents in review. In addition they got a manufacturing line they can innovate on and a lot of talent.
Also, MM has 3.5Bil in cash reserves. That means that it's actually 12.5 - 3.5. So, still a better deal, I would say. Then again, that's just a CS student talking - I have no idea what these patents are worth.
Edit: Formatting.