Well I am most in favour of just starting with a blank slate.
(definatly not that idea of our races comming to the original mass effect galaxy with the races still there because then i'd have to rewrite my entire race from the ground up)
Also, I'd like to weigh in on that camouflaged ship. The idea is good and I don't see why you can't use it but it won't be very useful.
You see, in space, you can hardly work off of visual scanning given the massive distances involved.
Sensors pick up heat emissions from other vessels and so a ship that just obscures its visuals will still stand out on those sensors.
A stealth system like that of the Normandy works because it stores its heat emissions in special sinks but that only works for a limited time and not while in a combat situation (because operating weapons would generate too much heat).
In fact, heat is the major limiting factor in space combat because larger ships especially can only go on for so long before they have to vent their excess heat lest they boil their own crews.
That said, a visual camouflage system on a smaller ship is still rather handy when landing on alien worlds, if only so the locals don't just plain 'see' you. In addition, it'll probably fool any defensive system that works off of laser targeting (such as Kimo point-defence systems for example)