This section is still under construction so it is blocked from crawling: http://www.quebecguitare.ca/video

Also, I just logged in to my GWT account.

What is the best practice for this case. I maybe too naively listened to the advices from google telling me to submit both www and non-www site.

I use redirect non-www on htaccess.

Now I get this messag from GWT:
http://quebecguitare.ca/: Googlebot can't access your siteDec 13, 2014
Over the last 24 hours, Googlebot encountered 18 errors while attempting to access your robots.txt. To ensure that we didn't crawl any pages listed in that file, we postponed our crawl. Your site's overall robots.txt error rate is 37.5%.
You can see more details about these errors in Webmaster Tools.

..and as well while I am at it:
http://www.quebecguitare.ca/: Increase in not found errorsDecember 7, 2014
Google detected a significant increase in the number of URLs that return a 404 (Page Not Found) error. Investigating these errors and fixing them where appropriate ensures that Google can successfully crawl your site's pages.

Regards