Is the life of the joint at the t-case effected by the torn boot?

Is there a certain end to drop from? If I follow instructions on how to replace a shaft, but don't pull the flanges, is that pretty much it?

Yes/-all newbie questions.

 

No, the life of the tcase joint is based on angle and use. If you look at the tcase output, you will notice that it angles upwards, which adds to the joint angle. The rear of the tcase is pointed down, so the rear shaft has decent angles. (lift height, shock length, disconnected or not, all onroad vs max flex offroad, luck, etc. A combination of factors will affect how long that joint lasts).

And both ends minus the flanges, just unbolt it and pull it out. That way you can cycle both joints by hand to make sure they are still in good shape, and you can pull the entire shaft apart if needed to check the slip joint. If you don't want to drop the shaft, at least undo one end so you can cycle the slip joint in and out.