I have a surface tablet computer with windows 10, and I've never seen an app that I would want on my PC that runs DCS. There is a snowball's chance in hell that DCS will upgrade to DX12 in the near future, but if it does, I'll upgrade to windows 10.
As for the sound issue, other games will automatically install the drivers you need to get sound working again. I think it was after I reinstalled Cliffs of Dover on steam that sound worked for me again in DCS after an OS reinstall.