keleja

If the s7's were going to explode, they would have exploded months ago, because the note 7 is a very new phone, and the s7 is multiple months old.

There are no known cases of a Galaxy S7 exploding or anything similar. Only about 1/50,000 Note 7s and 1 Galaxy Core Prime with a fake battery.

The phone draws current from the charger, current isn't forced from the charger to the phone. If the phone can draw a max of 1amp, even a 2amp charger will only give it 1amp. If the same phone tries to draw 1amp from a .5amp charger, it'll get .5amp. It's possible for the 1amp charger to not be able to hold a steady 5v at 1amp, yielding a slower charge. Was the same cable used on all?

For 2-4 bay solutions, it’s easiest to just buy a prebuilt.  They are usually way easier to use or simply more convenient.  4-8 bays are really the wishy washy area, where you have to start actually measuring effort vs cost.  More than 8 bays, and it just gets insanely expensive to buy a prebuilt since you pretty much have to go enterprise grade.