Your #1 is a feature of Windows Snap, which is disabled by DDM when Easy Arrange is enabled to avoid conflicts. Do a search here for "Kbfix" or "LeaveSnapAlone" for registry settings that allow Easy Arrange and Snap to coexist.

As for your #2, the dialog box automatically closes after ~30 seconds, allowing you to go back and make further changes to image levels and the preset mode for the active app without having to go back and reopen the dialog box.

(Agreed on the size of the close button.)

The end result is that the user must point to the tiny x to close the window. 5 sec time out or adjustable interval is more acceptable. 

So user has to click this tiny x every time. 

If they want to adjust the brightness of the image, hovering over the quick view should be enough to keep it open, and not having to click the  tiny x to hide it. Simply making the button slightly larger is not enough to fix the user experience flaw. 

I wasn't disagreeing with you, just pointing out that that behavior was by design and not a bug.

In the current rc, the small dialog box closes immediately when it loses input focus, just like the Windows clock/calendar.