1. A lot of Bitcoin activity is happening off-chain. Sadly, I would estimate that the number of users of wallet services increases faster than the number of real Bitcoin standalone wallet users
But this is sort of inevitable. First adopters, and those who came right after them, were quite tech-savvy, to say the least, so they had not problem to set up desktop wallets. And some of them started those wallet services (web wallets if I got you right). Right now, more and more people get attracted to Bitcoin who simply can't properly set up their computers (I mean make them safe from viruses, trojans, and similar things), let alone setting up a standalone wallet...
And web wallets come in very handy here
As I got it, the transactions from the top 100 addresses have been excluded from consideration, and I agree in advance that it cuts both ways
As I already said, it is hard to find a good metric to gauge Bitcoin adoption since Bitcoin adoption itself is not clearly understood and defined in the first place. Ask two people about what they think Bitcoin adoption means exactly, and you may get very different answers. Obviously, Bitcoin adoption by merchants and vendors means one thing, while by gamblers and traders quite another
This doesn't mean, though, that we should not at least try to come to a common denominator here