Can you help me figure out how long it takes to get POS reward?
Depends on your luck. It can be a month or more. Devs are staking with their premined coins and mining about 50% of all POS blocks. POS mining is very difficult at the moment.
I think it's only 40% of the premined coins that are staking.. and i actually don't mind that, as long as it is used for the development of the coin.
It's better to have a slightly smaller amount of a coin that is doing great than have a larger amount of a coin with lack of development..