Air link should work, almost out of the box with the spec you have. Something seems too be compromising that. VD and fpsVR, between them, have decent tools and information to help to see where about the latency, and potential GPU / CPU bottlenecks, could be coming from.
Perhaps wrong, but, as noted, I would consider installing the Meta software cleanly on your PC.
Being really new to VR, first headset a Quest 3, and Air Link, Steam Link, VD etc all seemed to work as expected. Just dialling in to see what suits, like for us the room where the router is, biggest floor space, is the one where the signal is the best and so that will be primarily used.
I now have a cable, able to inject charging into it, for sat down PCVR titles when I get round to testing that more, and using the Dev tools to increase bitrate etc.
Chances are if you get air link to work as expected perhaps other issues will be resolved. Good place to start.
Surprised at your need to troubleshoot, so much.