Only certain SSRs can be awoken, yes. Currently only Gaia, Tyr and Thor can be awoken in our version.
Our version is basically a year behind the JP version (because it launched about a year afterwards), and it gets features/events at basically the same pace the JP version did. Occasionally they change the scheduling of events a bit (following the JP schedule, the next even would be the Typhon/Garuda rematch, but we already had that - and they changed the scheduling of the Kohime Musou crossover), but outside of that we get things pretty much on pace. Considering some of the other problems other DMM-Nutaku titles have run into, this game's level of support is pretty damn good, I think.