Idk what is causing the corrosion. On my rig the breathers were extended and the seal housings were not corroded. But my seals were toast, that being said the lockers had been in my rig for 13 years. That's plenty of time for an o-ring to give up the ghost.
The guy who owns sand hollow offroad and owned moab 4x4 for years told me he saw the issue all the time. According to him the arb seal housing would even become corroded on a lot of the lockers and new seals wouldn't fix the issue.
100% correct
The Detroit in my 91 would make the rear end slide off the road in any kind of slippery off camber situation. Ie snow, ice and mud.
Other than that I had no complaints.
If I was doing lockers I would go Eaton/Harrop all day long. I just had to spend a lot of $$$ and time pulling my 3rds and changing seals on my ARB's because they were leaking so bad.
Electric all the way, the only reason to go oem would be if you already had them.