Is it true if u use the spell card "creature swap" u can destroy ur opponent's monster that u swap?

no its not true, u and ur opponent choose one monster th swap. not destroy.

If anda use the spell card "Creature Swap" on your opponent's monster that anda swapped with your own, anda CAN sacrifce the opponent's monster for a stronger monster. I used it once.

Unless it says anda can't sacrifice the opponents monster then I don't see why not. I think anda can sacrifice their monster

Yep! ^^ I use this strategy when I only have a weak monster and sacrifice my opponent's monster for a stronger one. ^^ I read up on it online.

Its a very good strategy to use