The high E string noise might be a saddle issue or the string itself might be bad. I wonder if the B string issue might be resonance through the neck and body causing the E string to oscillate. Does it change if you fret the B string?
I had the same issue with an SE Paul's. Seemed to be location dependent; noticeable at my house, really bad at my neighbor's house, completely quiet at the tech's shop and at lessons ( same amp). So I chalked it up to "dirty power". Reply from PRS Support stated that a bit of hum or buzz was not...
I often feel inconvenienced by the perceived lack of action on other's parts, but then I realize it might be my own inflated expectations driven by first world privilege that is the problem. Not always, but often.
Maybe it's the seemingly unstable and confusing state of affairs here in the US and worldwide influencing your dreams. Even if you're not consciously worried about it, it may be lurking deep in your subconscious.
I did the "drop test" with Tusq vs PRS USA and the Tusq rang out more than the USA. Now, whether that translates to real world tone results, I don't know. I do know the Tusq sounded better installed than the SE nut it replaced.
I used an Oak Grigsby in an SE custom 24 and it fit. Take note of the spacing dimensions to be sure of the fit. Should be available wherever you buy from. There are other brands such as Switchcraft which make decent switches.
When I did a similar re-wire I just googled "2 humbuckers, 1 tone, 1 volume, 3 way blade switch diagram" and was rewarded with many diagrams to choose from. Also, I'd replace the SE switch if you weren't already planning on it. I think I used an Oak Grigsby brand switch...much beefier than the...