That 1% is a lot in my opinion, taking into consideration this is just a corner of the glacier, I guess there maybe in total 5% lost..
I wouldn't be surprised if it is more like 2M BTC lost. In the first year+ of Bitcoin's existence (during which almost 2M coins were mined) it was nothing more than an interesting experiment. The coins were worthless, and people treated them as such. I mean heck, the first known monetary valuation wasn't until Lazlo's pizza, which was mid-2010, 1 and a half years after it started. Not to mention than Satoshi himself mined a good 1M BTC, and I don't expect those will ever move.
Just my best guess on it. I'd be willing to bet that 10 years from now, there will be at least 2M coins that haven't moved between now and then.
Yes, all bunch of coins and the majority of them was lost in the beginning, when Bitcoin was still worthless. I agree on this with you. On the other side, 2 million lost coins is a quite high number in my honest opinion.
I don't really know what to think about Satoshi coins. I like to think that he will wait until Bitcoin really makes it big and get mass adopted, and then he will donate 95% of his coins to the hungry people of the world. This would make him pretty much a biggest man on the planet that has ever lived.