What is the way to reposition an item on the screen using the CMS ? I see there's move forward or back menu items,
which don't give me much flexibility.  for example, I'm trying to position the logo center-aligned, how do I do that ?

That's what the block container is for. You could add your own block container or chang the existing block container by using "Advanced". Apply any html or css style as you wish.

Another way is to use Html Block. You just add your logo as an image and adjust alignment by using the UI,

Not sure what you meant by "using the UI" to align ? UI of which ?
But, I could get around by creating a 3 column block, and keeping the logo in the middle column.  Let me know if I missed some tricks for alignment.
The advanced menu is little cryptic, not sure what %%31%% means ?

Another Questions :
The blocks that  I add in the left or right side on default page, shows in all my newly created pages, is it by design ?
or, I can customize the right, left contents per-page basis ?

UI of Html Editor.

I would suggest you don't change anything wrapped in %% in "advanced" dialog. Instead you should use the "Edit" to change the width of columns. Why don't you just change the one column block container by setting style="text-align:center" to the div element?

Yes, that's by design. You could disable side columns by editing the page block per page. Or you could set the width of side columns to 0px to hide both columns for all pages.

Luke :
Where should I modify the the style for a specific block ? in the default.css ?
sorry if the question is too dumb :) still taking time to learn the CMS ?

Do you have any plan for a webcast for like a developer walkthrough kind ?
I saw the introduction that shows how to use it ? but if there was one that describes the general architecture would be really nice.
Thanks
KM

You might want to use Site -> Templates -> Default.css to add more css. If you want change a theme completely or create a new theme, check this thread http://support.dotshoppingcart.com/forums/Home/tabid/36/forumid/5/threadid/86/scope/posts/Default.aspx.

Yes, I always want to create some tutorial videos. A video is better than thousands of words. We are in very tight schedule to get V2 open source and commercial edition out.  I guess I will do my best to find time to get something out.

what is the expected timeline for the V2 editions ? I'm specially interested in Onepage checkout module, that you mentioned some other place ? will it be possible to buy a checkout module that can be used with open source edition ?

Open source V2 is scheduled to release by the end of Feb and the commercial edition is by the end of March. Yes, we will provider addon modules which are intended to work with the open source edtion. The commercial editon is also built on top of the open source edtion. One page checkout and a<span style="font-size: 9pt">nonymous checkout will be one of the addon modules.</span>