Thanks for your feedback!
Sorry for delay, I was on holiday and did participate in WordCamp Europe in last weeeks.
Back to your topic:
From what you're describing it's the correct behavior. Your plugin settings show full width for home page and all pages - that should work fine. And yes, in these cases the sidebar shouldn't be there on home and on pages at all.
I see no reason why it shouldn't work with DWB, otherwise you did customize stuff regarding layouts which could lead to potential conflicts.
Where is your blog page located? On homepage? Or did you setup a regular page with the "Blog" page template? -- In both cases your above settings would have the higher priority and override it. If you have a page with the "Blog" page template you could try to set another layout in the inpost layout settings for that page.
Does that help?
Otherwise I need more details or a test account on your site.
Thanks, Dave :)