I can not see and confirm at demo site. If there are more then 5 featured article, is there any slider of this section to see the rest of it at blog main page ?
There is a slider setting actually. Can maybe do a video or screen on this. Yeah it shows up on the index page template. So you choose a page (Call it Home or whatever) then set page template. Then mark a post with the 'featured' tag. Actually we can update documentation on this as not sure if we have anything.
Another question. I am using UIX.2. I guess after the installation of Xpress, there will be fully integrated thema including my custom header section. Is it correct ?
There is a theme packaged in that will make it so your WordPress uses your theme on XenForo, so yes you'd get your customer header section. Its all single code, so you don't need to update two systems, theme just "works" thats the magic of this product. Not an easy thing to do performantly.
If we can see some real users’ real web site that is integrated with Xpress, it will be very great.
Agreed, Id love to see demos as well!
Is it able to show both left and right sidebars? And we can use the XF2 widgets throughout?
There is a page template to move sidebar from left to right (or you can do it globally like you do in UI.X in style properties). Itll default to whatever XenForo setting is.
so it means you can edit users threads and turn them into articles right?
Yes, if you have the moderator permission to do so, thats correct. You can "perfect" them in WP. But promoting will sync the thread with the article as well, if you have that setting on.