Increase the sensitivity of Asus WL-500gP Hardware mod.

[lly]

When I use the wl noise command, my router gives me a value of -24. Is this good or bad?

If Wi-Fi is turned ON on router, this shows that there were strong noise source near router, i.e. this value is very bad.

Should I still apply the fix or not? Also, what is the physical size of these resistors? Is it 0402?

Your router is buggy, but fix it is up to you - to make decision you have to reread threads on this forum and OpenWRT forum. R17 size is 0402.