The premine was "only" 1 million. His math is right, 0.7% of 133 million is 1 million. 7% is 9.3 million.
Still not going to mine it, because why do you need that large of a percentage of the coins, but his math is correct.
10,000 is more than enough for bounties and such.
yes, made a mistake there. 0.7% is 0.93 millions. (133m * 0.007)
Nevertheless it is a premine of quite a lot of coins there.