Edited the post a tad; the idea I left out was Shuttle Missions, which I've managed to implement (also got a screeny up, although it doesn't show a whole lot)
As for classes unlocking at levels...well, I've been toying with the idea of adding requirements to unlock the classes, but not sure whether or not I want to. The idea was that you always have access to your classes and characters and only small bonuses from levels and gear are acquirable over time.
Although I also don't know how to code in a class level requirement with the script.
The obvious idea I had was to just make a mission that would unlock it, but am still deciding between that and just having it freely available.