I found the fact related to the second question by qt-Wallet, help > debug window > console and "getblockbynumber 10000"
The first 10,000 block was premined by PoW.
How much is block reward?
If the block reward is 10,000 SAKE, which is equal to that of black coin, you get 100,000,000 SAKE by premine, which is  one-sixth of total coin supply.