INFILTRATE MY ENEMIES: Before placing characters in your starting area, you may choose an opposing character that is 100 points or less. Copycat becomes friendly to that character's force and that character becomes friendly to your force. Any game effects assigned to each of them is now assigned to the other. When Copycat fails a roll for Shape Change or uses Regeneration, after actions resolve, this effect ends and any game effects assigned to each of them is now assigned to the other.

Where does everyone get the idea of swapping characters? It doesn't state to swap. I am understanding it as Copycat is on my team but the opponent's team cannot attack her due to her being a friendly character and my team cannot attack opposing character. I view her as more of a tie up piece by basing up to opponents and preventing them from moving or to block line of fire.

Can someone explain to me how to use her correctly.

The "swapping idea" is because she becomes friendly to your force and your character friendly to the opposing forcé before placing characters in starting areas so when you place characters in the map your piece is not longer in your team but now Copycat its.

Although your idea of Copycat's power sounds less broken and more fun

When a character is friendly it is under your control and vice versa.

Rulebook pg. 2

For her to work as you say you would never get to roll for Shape Change as you cannot target friendly characters with an Attack (yes there are exceptions to this, but they are limited). So for her to end the player who owns her would have to willingly push her to Regeneration and then use that power... In Other words it wouldn't happen.

This figure is going to bring up too many questions.