A question about short stories and publishing.

I have a deep interest to get one of my short stories published in a magazine or e-zine. I was hoping to talk to someone who has done this before. While, I do know quite a few places to submit my writing, I was unsure of two things.

1. Is it okay to post the short story on my blog until it is picked up to be published? Do I have to remove it after?

2. The short story takes place in the world my novel is about. Is it a good idea/bad idea to post a story about your world before your novel is published? I feel like it could generate interest…

Anyone who wants to comment and give me their experiences and opinions is much appreciated!