Hey BHW a few questions :)

Hi im digitaldagger and im new here I was wondering whats a safe way to sell something in the BHW market place? How do most people accept payments?Also if i was to make a thread am i allowed to link to another thread? like "Id like to thank Alice's thread for helping me do this"And how many posts until i can change my picture

oh and another thing may i link to my fiverr account if i am selling a product on the bhw market place?