Does the door close with this on?

The door closed perfectly. hooks hold lots of coats. sturdy

Will hanger be too loose if my door width is 1 3/8?

This over door hook is perfect for doors that are 3.5cm (1 3/8 inches) wide and have padding,

it fit most standard door up to 1-3/4" thick

Door hanger for 1 7/8 width door?

NO, This over door hook fit most standard door up to 1-3/4" thick

How much weight can a one hook hold?

It is extremely sturdy; it can hold a lot of weight. A large bath towel.

How many items can you hang from it?

This door hanger can hang More than 12, making it ideal for hanging coats, hats, bags, and other accessories.