So I have only the problem described in Post 1
The first post is from 2011 and relates to OMV 0.2.5 and if you read the solution -> install kernel modules so as to use the DOM, the same is true today except both Debian and the kernel have moved on.
Suggestion would therefore be to try a Debian NetInst the link is for CD but it can be done from a USB, (this should be a minimal install ssh only and basic utils). If that works then ssh into the Debian install as root and follow the instructions here and run the script that will install OMV .