If i bite too hard will i crack my teeth? why do some foods with interesting textures slip around wile i'm chewing?

Biting: You would have to bite pretty hard on something pretty strong or have damaged or weak teeth to break during normal chewing, even if hard. The ligament that holds your tooth in the socket has proprioceptin that stops you from biting down too hard. There are grooves in your teeth so different textures and sizes may pass through differently than others.

It is possible: If you have very strong bite forces, and especially if you have teeth weakened by large fillings or other dentistry, it is quite possible to crack your teeth. It also happens more on people who grind. See your dentist to see if this has happened, or if you have any teeth that are at risk. Also avoid ice chewing, hard candies and nuts, an never use your teeth as tools for opening things etc.