You have to understand that those words are English word :)
so you can use both of 자켓 / 재킷
But, normally used 자켓.
신발 : All kind of shoes (sneakers, high heels and so on)
구두 : normally Korean used this word, High heels and dress shoes...
so 신발>구두, 신발 is more bigger group then 구두.
원피스 : One piece
드레스 : Dress
... That mean is same. But Korean used that word likes
드레스 is more luxurious, elegant
원피스 is casual dress
배 has quite a lot of means!
Stomach, Ship, pear...
So, when you want to say 'pear', you can say 먹는 배(eat)
if you want to say 'ship', you can say 타는 배(take/ride)
if you want to say 'stomach', you can touch your stomach(lol) or you can say 사람의 배(Human's)