I don't see that "OAD" being a torque converter of any kind. It is just another one-way
clutch.
All the excessive belt tensioner movement, and the excessive belt movement, can be caused by the clever vendor simply not having adjusted the belt tension correctly. Could be a bad tensioner (a big problem now with serpentine belts) or it could be a wrong belt.
Clutches aren't used on alternators normally because they add mass and drag and expense. When the
electric system is not putting any load on an
alternator, it creates very little drag on an
engine. Newer car "power management systems" actually SHUT the alternator when the
battery reaches full charge, and leave it shut until some specific point is reached (i.e. 95% charge or a large load) so that the alternator freewheels and the
engine gets better mpg when
power is not needed.
A solution in need of a problem, as opposed to a robust "just buy fuel" solution. Clutches,
computers, all less reliable than "just buy fuel". Especially when the tensioner seizes up and takes all the rest with it.