Input management has been changed quite a bit in ViEmu for VS 2010. Since the new editor is WPF based, we cannot intercept the key presses the way we did in older versions. Instead, we create VS commands for each possible key combination but by default we leave most of them not assigned to any key combination, so that we don't mess with most keypress assignments that people or other addins may have configured.
To the point... all you need to do to make those mappings work is go to Tools->Options->Keyboard menu in VS and assign the key combinations to ViEmu commands, for example:
Assign Ctrl+H to command 'ViEmu.KeypressCtrlH'
Also, I would suggest that you choose 'Text Editor' instead of 'Global' in the 'Use new shortcut on' combo. This way the ViEmu command will take precedence over other commands that may have the same key combination assigned.
If this doesn't work, please check that the key combinations are not assigned to other commands that may have higher priority.
I hope this helps...