Using a flat iron on your perm occasionally won't remove your curls permanently. However, it can damage your style over time. You may ruin your perm, and the heat from the flat iron can cause hair breakage.
Yes, but you need to be careful to use the same chemical that was applied originally. If you're not sure what was used on your perm, perform a strand test...
Try blow drying it. Also, using lots of products weighs down your hair, making it flat. Sleeping with your hair wet may help it be bouncy and shiny in the...