Isn't my BMX (Mongoose subject 2011) is too heavy to do some trick, ex. bunny hop?

I would not trust my body to a newer Mongoose for BMX. Those bikes are NOT meant for tricks, despite their advertising. I had a friend who took his 2009 Mongoose to a park, where he bunnyhopped off a ramp and the frame cracked, and the arm fell off of the forks. They are cheaply made, the metals used are cheap, and are not constructed to face such stress. Leave the K-Mart bike for leisure riding, and get a 1990's Mongoose, or go with a good bike (Haro, Verde, Sunday, ETC) Weight on that bike isn't a problem, its the construction. I have a Haro F3 which I customized and it is built like a tank.