So do these things swap or do they transfer all xp from one character to another. I mean there's a difference right. Like if I want my main character to have the highest stats then I'd transfer all my exp from alts to my main. However if it is a swap that would be a bad thing to do.

The answer can be found in the coupon name.

If it says "Transfer" it transfers all exp from one char to an other.

If it says "Exchange" it exchnages the exp of two chars.

In your case the coupons are called "Strength EXP Exchange Coupon", "Breath EXP Exchange Coupon", and "Health EXP Exchange Coupon".

So they exchange the strength, breath, and health of 2 chars.
e.g. Char A has strength level 30 and char B has strength level 5. After the use of the coupon char A has strength level 5 and char B has strength level 30.