just another thought amongst all the many:

I was having severe pain in my elbow on my comfort bike. When I started talking to my LBS guys and paying closer attention to my riding - I discovered I tended to "pull" on the bars whenever I was climbing or standing in the pedals. The comfort bike had seagull?? mustache?? bars - don't know what they were called but it had a slight bend in them and I was trying to either get in a more aerodynamic position or using the bars for leverage. Either way - when I stopped pulling on the bars (and switched to flat bars) the elbow pain went away.
So, are you pulling against the bars?? Plus what everyone else said - your arms and hands don't "look" comfortable to me anyway, they look very awkward and tight.