Progress: Both rotors are off. A few seconds with the torch and they came off with a light tap. They look reasonable but maybe a little thin so I'm likely to replace them, too. Probably just from the dealer ... considering hitting NAPA instead though.
Speaking of NAPA, I went there and asked about the Loctite 574 and he looked it up, dug through a couple books and called Permatex. They told him what the equivalent was, and it is indeed not red threadlocker ... it's an anerobic gasket-maker that sounds exactly like the description bio300TDTdriver posted. I'll post the product number when I get a chance. I still don't really understand why there's a sealing compound between the joint and cover plate, seeing as it all ends up covered in grease ... but going by the book seems like a good idea.
As for the axles ... I think I'm just going to reboot the outers, while cleaning, repacking and rebooting the inners. The FSM doesn't describe cleaning the outers, and I think if I try I may just mess them up seeing as they're not removable and difficult to access. They look full of grease and the grease looks 'healthy,' and the boots, while beginning to crack, were no way near cracked through (even that one big crack wasn't through). Sound sensible? I will add some new grease to account for grease that came off in the old boot.
Still can't get the one inner joint off ... PITA ...

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1987 300D, arctic white/palomino--314,000 miles
1978 240D 4-speed, Euro Delivery, light ivory/bamboo--370,000 miles
2005 Jeep Liberty CRD Limited, light khaki/slate--140,000 miles
2018 Chevy Cruze diesel, 6-speed manual, satin steel metallic/kalahari--19,000 miles
1982 Peugeot 505 diesel, 4-speed manual, blue/blue, 130,000 miles
1995 S320, black/parchment--34,000 miles (Dad's car)