I'm going to lump this into one Feedback item, but perhaps it should be broken up.  I took some notes while attempting (and never successfully) using the manual merge dialog in VSB.  This seems really important for one main reason: many people base their themes off of your Built-In themes.  When a new release of UI for WinForms comes out, with a new control like the CollapsiblePanel, it's tricky to get that added to your existing older theme (which is the scenario I'm dealing with right now).

I've ordered these items in the order of importance (at least to me =] ).  I think the main thing is the on-screen help and terminology used to describe the items on the screen being confusing and inconsistent, but I do believe there are some bugs and/or missing features to make it functional.

- The text in the merge dialog refers to a "Destination" and a "Source" theme everywhere except on the DataGrid column which refers to "Existing" and "Loaded".  If I have a theme open (let's say MyOldTheme.tssp), and then I open another theme (TelerikMetroBlue.tssp) it triggers this dialog to open.  Which theme in that case, is the Source/Existing/Destination/Loaded?  I think this should be clarified by making it clear which is the source and destination and sticking with that terminology, or call it something like "Item Loaded" and "Item Loading".  Also, in which order should I open these two themes if my end result is to get one control or a set of repos merged into MyOldTheme.tssp from TelerikMetroBlue.tssp
- Everything is detected as a conflict.  Real conflict detection should exist where it only shows items that are conflicting (i.e. the item exists in both files but there's a change).  You can open a file, and then open that SAME exact file and every repo item is red and considered "conflicting".
- You show a comparison grid, but I can't see any way to resolve the conflicts it finds.  It doesn't let me choose which value I want, the source or destination.  
- There's a lot of text describing how to deal with the conflicts on this screen, but after reading it I was more confused than I was before.  I think this needs a lot of clarification, and should be written better.
- The "Existing" and "Loaded" columns in the grid have their names cut-off, don't support column resizing, and don't have a tool tip.  The only way I could see that they were called "Existing" and "Loaded" was by going to the column chooser, and removing the columns (since if they're added to the grid, they don't show up in the Col Chooser)
- I think the "Existing" and "Loaded" columns should be immediately next to each other for easier visual comparison of the two.  By default there seems to be a random text field thrown in between them (they can be manually re-positioned, though)
- In the column chooser there's a IsSelected column I can add - does that have something to do with the merging?  What does "IsSelected" represent? Choosing the item from the item already loaded, or the item I'm currently loading?  It doesnn't seem to do anything, but I could be wrong.

To reproduce:
- Oped a predefined theme in Visual Style Builder
- Change an image property of an element that already has image (set it to a random local image).

The issue occurs only in Windows 8.

To reproduce:
- Open the TelerikMetroBlue theme and select RadPanoramaElement in the Control Structure window.
- Expand PanoramaBackgroundImage element in the Elements window.

 Please note that the issue occur only in Windows 8.

It would be great to have an auto-save feature in Visual Style Builder for when/if VSB crashes or quits improperly and theme wasn't saved.  

See my forum post for more information, at: 
http://www.telerik.com/forums/visual-style-builder-frozen---does-it-do-any-auto-saving

Resolution: Under Tools>>Settings in VSB there is an option to enable/disable saving auto recovery info and the interval at which this info is saved. The auto recovery data is saved as a .tssp file in the C:\Users\<username>\AppData\Roaming\VsbRecoveryData\ folder. The mechanism is as follows every X minutes the file is overwritten with the current state of the theme in VSB. If VSB is closed gracefully or the theme is unloaded the auto recovery data is deleted. If VSB crashes the data in the auto recovery folder remains. On the next VSB start this folder is checked for content and if there is any the user is offered a choice to load this content.

To reproduce:
Start VSB -> RadButton -> RadButtonElement -> ImagePrimitive - Image -> Browse for image and you will see no change.

Workaround:
Start RadControlSpy using Ctrl + H, select the button, browse to the ImagePrimitive and set the Image property

Resolution: 
The described behavior is not an issue. The image should be set to Image property of RadButtonElement instead of ImagePrimitive. 

To reproduce:

Open VSB go to RadScrollablePanel -> RadScrollablePanelElement -> FillPrimitive and change its back color, you will see that the back color will not actually change.

Workaround:

Set the BackColor using code:

panel.PanelElement.Fill.BackColor = Color.Red;

In the winforms visual style builder app, under View > Settings > Design View, unchecking "snap to grid" doesn't prevent control resizing from snapping to grid.  It still forces it to increment/decrement the sizes by 10 pixels based on the Grid Minor Tick settings.  Workaround: set grid minor tick size to 1px.

To reproduce: 
1. Open ThemeViewer 
2. Choose theme Desert 
3. Check View RTL support
4. Check 'Aero mode on' of ribbonbar & backstageview, after that click on 'show form' button
5. Check 'Aero mode on' of RibbonBar & Office2007 App Men, after that click on 'show form' button and will see that ThemeViewer crash
When set theme Desert and change values of the properties of RibbonBar in the VisualStyleBuilder generate the same error.

Add the ability to style RadCarousel via Visual Style Builder.

VisualStyleBuilder  - does not load all states if the theme is loaded from XML files.

Currently there are many cases where there is too much wasted space. The property grids sizes are fixed and they do not fill the available space in the most optimal way.

Add a VSB feature to export base64 strings.

The Text and Image Primitives of RadButton are not exposed in VSB

Currently there is no way to export theme images as Bitmap (or any other image type).

Resolution: In Q2 2014 SP1 we introduced feature to export images from Visual Style Builder. The issue is the same like ADD. Visual Style Builder - add ability to export base64 strings to images (export image option in the context menu of all Image items). You can follow the link: http://tpdogfood.telerik.com/view#item/111008 

FIX. VSB - error when trying to preview a theme in ThemeViewer and the current directory is different

Open Package Windows7.tssp - RadPageView - RadPageViewStripElement - StripViewContainer - StripViewButtonsPanel - LeftScroll.  Edit Repository Item StripLeftArrow.  Click inside Image property to highlight - Unhandled Exception.

As suggested on the Silverlight PIT's, MAC like themes are very catching and adding a default theme for all controls with this style will be helpfull for developing app's with that desired look

FIX. Visual Style Builder - the color picker should keep the previously added Custom colors after reopening the form and continue adding to the available spots, instead overriding the existing custom colors.

Telerik Metro theme is not exported by VSB

Currenty, VSB does not support GIF images