I\'ve got problem with automatically breaking StackPanel into next line. Here\'s the sample code:
Use VariabeSizedWrapGrid instead of StackPanel, see http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.controls.variablesizedwrapgrid.aspx
For the multiple TextBlocks, consider using a single textBlock with multiple Runs. Your Image can of course not be included in the runs, but one TextBlock with two Runs is better than two consecutive TextBlocks.
UPDATE: This might actually not help you at all to get the layout you want. You may have to look at the RichTextBlock control, see http://msdn.microsoft.com/en-us/library/windows/apps/windows.ui.xaml.controls.richtextblock.aspx