Looking at the road map you set out I agree you should rethink 200% staking reward annually this will only lead to a huge loss of value in the future. Maybe set out a five year staking plain starting with 100% on year one and ending on 10% on year 5 and continuing with 10% for the life time of coin...

100% year one  3000 Vaultcoin
50% year two    4500 Vaultcoin
25% year three  5200 Vaultcoin
20% year four    6240 Vaultcoin
10% year five    6860  Vaultcoin

I done the figurers in my head so I know is not hundred percent correct, just rough guide line.....
Sorry could not see how a 200% staking reward will do any good for this coin then lead to a huge loss of value .