My first POST here and I must first say that OMV looks very good!!
After installing OMV I switched over to my laptop accessing my OMV server over wifi. Now Wifi isn't fully secure so I think that it's a good idea to enable HTTPS either by default (could confuse users as a self-signed certificate is not trusted by the browser) or at least hint something about HTTPS in the startup instructions? There were recently some updates of the startup texts but no mention of HTTPS as far as I can tell: http://sourceforge.net/p/openmediavault/code/499
Another minor improvement could be to highlight the required field on the Self-signed SSL certificate page. I think that you only need to set Key Size, Validity, CN and Country. The default key size could also be set to 2048b to align with the current recommendations.