lebih kurang. apart from needing two gpus for each OS (for best performance), the base OS needs to be xcp-ng, esxi or unraid. setup a VM with resources that you want for Win10 and Mojave, and perhaps another VM for Xpenology.

Can run Hassio also 

proxmox is also fine. just that in most comparison promox is often considered to be for a more advanced user. you can use whichever host OS that you want.

personally after trying them all (with my limited skillset), in order of ease of use to paling mafan:

esxi
xcp-ng (can use xen tutorial)
unraid (once you understand this should be the best IMO)
proxmox

but if proxmox makes sense to you, use it! nobody's stopping you

doesn't matter if you're an exclusively solitaire player, if you want your VM OS to see your GPU, you need a host OS with GPU passthrough. in this sense, Xpenology can only passthrough intel iGPU. and while all of the above OS can indeed do software RAID, it's just not as good as a dedicated NAS OS like freenas or xpe. hence, my earlier reply
Note that if you like your hair, only use radeon with hackintosh.