2 weeks after launch to start mining. Because it is enough to prepare pools and also the launch enthusiasm is still existed.
4 weeks after launch to start multi-pool which will engage more Hash to make the price up dramatically. Just like Dark, Black coins.
Solo-mining only (no pools will be created for eXocoin and they are in fact a (slightly) disadvantage over solo-mining)
If it's only solo-mining I dont think it will be attractive enough for the miners who owns a great number of GPU, hardware and hash. Exocoin should consider pool mining and multi-pool mining as it will get everybody together to pursue profits which was proved by a number of coins such as Dark, Black, Doge, etc.