I would not worry about multiple H1 as a major issue .( as long you are not over doing it )

MattCutts :

http://www.youtube.com/watch?v=GIn5qJKU8VM&feature=player_embedded&noredirect=1

Some browsers might hide the www and htttp part from the url . Just to make sure pop your sites url in there ( http://www.webconfs.com/http-header-check.php ) and see if there is a redirect.

Rel canonical : does NOT redirect the pages .. its just there for search engine bots. Think of it this way

You would want to use rel canonical where you need to show the duplicate pages for users .. eg : on a shopping website sort by A-Z , by Price , Z-A, etc could all display the same things in different order BUT users benefits from having those so use a rel canonical there to tell the spider its all the same version of your " original page " . There is no redirects here users can see all the multiple versions of the page. If they are redirected what is the use of sorting those results ?

I would also like to know why OSE does that ( some one from the staff could possibly answer that )

In regards to your question : Should my non WWW be redirecting to my WWW ?

You should only allow one version it can either be non WWW or WWW. In your case stick with the one that has more authority and do a 301 redirect for the other one.

In regards to your question : Why am I getting two different domain authority and backlink counts ?

For Google  www.yoursite.com and yoursite.com are 2 different sites on the same domain.

Hope that made things more clear for you

No worries .. If you happen to come across a better strategy .. do drop me a line . I would be interested to try it out ^_^

Ideally it would be individual pages for those cities with unique content. I would include the content to talk a bit about those suburbs + what you guys offer in those suburbs.