not good

1. if you has Chinese passport while holding a J1 with 2 year's law, you cannot escape from J-1 waiver because there is treaty betwean China and US, even you change your citizenship after you get J1. So your european offer will not help.
2. If you already apply for J1 waiver, you will take risk of being rejected for new J-1 when you leave the country.
Be careful!