3. Will BlackRock and the central bankers be able to fork BTC into a proof of stake coin? ( How are changes to BTC created ?)
Thanks,
Ron
3. I guess it's possible if they will acquire at least 51% of all Bitcoin hashing power.
Anyone, as stated by stompix, can fork Bitcoin. They don't need 51% of the hash. They just need to modify the code and create their forked version of Bitcoin. Earlier altcoins are forked from Bitcoin. So yes Balckrock and central bankers can fork Bitcoin.
1. Is it correct to assume that each halving will result in a 50% reduction in rewards?
( If current reward is .0003 BTC, reward after halving will be .00015 ) ?
Yes it can't be called halving if the current reward is not halved.
2. Is there a good calculator for ROI and estimated rewards ( per day ) that calculates 5-10 years in the future or allows an input for estimated future value of BTC ?
No, no one can predict the estimated reward per day that calculate 5-10 years in the future because hashrate and difficulty regularly changes plus the demand factor is also unknown.