Was there an ICO/Premine/Instamine for the Radium Coin?

No. The coin was launched in May 2015. There was an approximate 2 week Scrypt Proof of Work period, followed by decreasing PoS rewards. The PoS reward has recently been adjusted to 0.5 RADS per block, as per the August 29th Hard Fork specifications. For more info on this, please visit our technical details page.

Furthermore, due to the lack of any sort of presale, a development fund was introduced to help offset cost of operations. For more info, please see our Development Fund page.