Just completed a new build, using an Asrock H370M-ITX board and 1.04b loader / DSM 6.2.2-24922, all fully functioning without any hassle or additional drivers. With 6 onboard SATA ports and 2 Intel NICs this is an ITX board to recommend.
Your CPU is not compatible.. It needs some additional instructions that Haswell has (and Ivy Bridge does not).
It needs to be 4th Gen or better for DS918.. No way around it - even in a VM..
You CAN use DS3615 or DS3617 though..