fyi, I'm cycling through from the beginning of this thread, so forgive me if I haven't seen a subsequent post that addresses the items I touch on below. (totally suggestions, mind you!)
1) nice fluid responsiveness and it captures the essence of the original default theme well
2) going from full width to the next width down (tablet?) is quite a noticeable jump from a desktop browser perspective. From the sample categories used on the demo, there will be real stores with as many menu options and this may be a good width to start a slide-out responsive menu structure.
3) there's no actual change in "width" on the next size down, only a transition to responsive slide-out menus. I understand what you're trying to accomplish here, but we may be better served to have the 3-DASH menu icon on the actual MENU, instead of the words "Select Category" and the down arrow. And I would suggest replacing the current (top-right) 3-DASH icon with a GEAR icon instead, as that would more encompass the functions it "un-hides" when it's touched.
4) focusing solely on the menu selections alone, during portable device view, they don't lend themselves well to touch gestures unless there is more padding between each line. I would also suggest using the + to show child lists instead of mixing them in with the parent categories from the starting gate.
5) looking at the product details from the smallest width, everything will lay out nicely and uniform if centered at this width. And this is also a good example (as seen in demo at narrowest width) why buttons with words take up too much screen real-estate and are much better served by popular icons, eg: "Add to cart", "Add to wishlist", Email a friend", "Add to compare list" - replaced with a cart icon, heart or list icon, email icon, etc.
I hope my observations are encouraging and not the opposite. I think you've done a great job and are definitely heading in the right direction with the bootstrap approach. ;)
Thanks for letting me review & I look forward to seeing how it progresses!