Sounds good. I've always been on the look out for an RP based around a crew of a ship :) pirates only make things more fun hehe. 

When talking about galaxy based RP's aliens close to how Mass Effect does it seems only to increase the reality of the setting. Not everyone will be 100% earth born humans, some may be born on other planets and have slight changes. However five armed monsters that can only breath in the dust from the planet zortox might be impractical ^^

I would say something like an American Dad fish that can talk but has to live in a mechanical suit that helps it be human (like the smoke guy from hellboy) wouldn't be a bad addition. But I feel any alien races need to have a nice written lore to make them feel believable. It would be boring to have 9 different beings on a ship and neither even know where any are from or know their customs. ^^

Just my two cents hehe