I guess if you want to fix the sound of the stabs you can lube them with krytox, never heard of permatex before.
Don't sand the caps, just buy some cheap ones off of aliexpress, you can get some sets in the single digits, it's not worth the effort to sand them.
My best advice would be to tough it out and save up some cash to afford a good budget custom. You made a thread about it earlier.
By Permatex, I think they mean dielectric grease. Pretty common thing people use for stabilizers. They're actually one of the major manufacturers of all kinds of products from automotive gasket makers to windshield repair kits to anti-seize, so just saying Permatex doesn't really say much.
Don't care about rattly stabilizers myself, but it worked well for a squeaky spacebar stab wire on an F77 of mine, and having used it for other purposes in the past I could see why people would recommend it for stabilizers since it is cheap and available basically everywhere.
As much as I hate Razer as a company in general, the Huntsman V2's analogue optical switches actually make it a product that still fits a surprisingly small niche of extremely smooth contactless analogue switches. If I cared about getting the best possible modern linears, especially for games ... it would be on my short list.
I'm not sure why the emphasis is on replacing it outright for objectively inferior options in all regards besides maybe sound.