It's unclear why living abroad would do much to broaden one's dating gene pool. Certainly you can avoid white, suburban Americans in Japan, but good luck meeting someone who isn't Japanese. Outside of the USA and Canada most countries are very monocultural. For example, if you are moving to Sweden for dating purposes you should be sure you are into Swedish people before you go. It is far easier to date outside your race/culture in the USA. I'm white, and haven't dated a white person since I was in high school.

In regards to your ideal number, 6 at age 30 would be a minimum. Lower than that and your potential dates will wonder what's wrong with you.