Did the Win7 -> Win10 upgrade (64bit) without any issues. Thank you JSB for the tip!
Since, noticed 2 broken programs after the upgrade: Wavelab 7 (64) and Wondershare AllMyTube. For Wavelab I was able to find a batch that fixed it, but not for the Wondershare (which doesn't matter as I switched to another similar program that seems to work even better than Wondershare).
Haven't yet tried to install RM3 as I'm not into Beta testing, but will immediately as soon as the official Release version lands. Hopefully soon!