Alan Hume wrote:
there has to come a point where you say, "right, no more, done"
and, yes, we have reached that point but I would just like to get this one last thing
worked out, I don't know what Bill reckons, I would bow to his wisdom on this one
This kind of thing is up to you. For the book's purposes, I will most likely need to edit what you have to this point down a bit but that is not a bad thing. It is always better to have more and edit down.
That said, you as a GM can always use more info on a race you have designed. Even if your players fo not use it but you just have it as background info. I have tons of this sort of thing for all the races in Nebuleon (or any of my games for that matter). Stuff like gender relations, clothing styles, views on medicine and tech down to the trivial of what their pottery looks like. It is a case of picking what will be of immediate use to the GM and then you need to consider if we put a web supplement out with the extra stuff.
So, don't feel obligated to do more but if you want to write more go ahead...but start a new thread!