I've not had this issues. I try to minimize how much stuff I have open when working in RW, especially when running the game. When editing, I usually have RW, HeroLab, Evernote, 10 or so tabs in Google Chrome, Adobe Acrobat with 1-4 documents open, and maybe an image editor (usually GIMP).
When running the game, I usually ONLY have RW and HL running. I've run some games where I also have Google Hangouts running.
I've had RW hang, crash, or slow down, but have never had repainting issues.
Screen refresh issues are more likely a video-card issue than anything else. Do you have this issue with any other program?
My computer specs are: CPU Intel i7 2.9 GHz; RAM: 8 GB; System Type: 64-bit Windows 10 OS; Graphics Card: Intel HD Graphics 4000, 1792 MB
Because of my graphics card, I cannot run many modern games on my computer, such as the new Witcher. But I've never had screen refresh issues like you describe.
Hope this helps.