Help with a few issues

Hi guys. First just want to say thank you for an incredible program, it really is making me very happy and nostalgic.

However I'm having a few issues. I've noticed with retro systems like genesis/snes, I'm getting some purple ghosting, and games feel slightly choppy.

Also N64 roms have crackling sound and awful framerates, and some gamecube games such as star wars rogue squadron have some performance issues that watching others play on stock dolphin on youtube don't have. I've looked online and it says I have to change some settings in dolphin, however I can't work out how to bring up the dolphin settings screen as the hotkeys that work in retroarch just put dolphin into windowed mode.

I have an RTX 4090 and Ryzen 7800x3d so I know it isn't spec related. I also haven't changed any settings on retrobat, everything is on default. It's also not the roms because it works flawlessly in standalone retroarch and other emulators.

Any ideas? I was wondering if monitor refresh rates and gsync etc could be affecting it?

Thanks in advance.