Wrong. Dueling would not cause any balancing issues, its a simple extension of pvp -- which is already being included in 2.0.

They did consider the swimsuits, and they decided they didn't want to do them this year,. They are going to do something else for the summer event and do swimsuits next year.

You need to understand that the game already flopped. The whole point of 2.0 is to introduce some new ideas and attract more people. If thats too much for you to handle, then you should find another game.