I'm getting confused by double spacing - they seem too long about 250 words each. Do I need to split them up? or is that ok?

Looking at mine, they mostly seem to be 150-200. 250 sounds fine but I agree that in double spacing it looks a lot more than it is. I reckon as long as it doesn't feel too long when you're reading and the subject within it is concise, then don't worry.

ok, I think 250 was my longest, so mine are between about 150-250 :-)