Re: Is it ok to to submitt a published blog article to article submission services?
There is nothing wrong with syndicating your blog content to article submission sites where appropriate, I see no penalty with this - however that is only if it is an article fit for submission. Blog posts tend to be a little more site specific or personal, so a lot of times don't make for great distribution.
In terms of DIGG: What you are suggesting I believe is close to violating their TOS - one should never DIGG someones post because they are asked, or because they belong to a group of DIGG account holders.
Of course this all depends again on the article: Have you read DIGGS categories or topics? None of them apply to real estate, so how would they ever make any real traction? I mean most true DIGG members would just bury real estate related content (Unless it was tech related)
Starting LEC 7 soon but it won't be called LEC 7 - LEC 2012 coming soon!