I am very want to know the account's level difference , and how can they have so colorful signature ? In addition , their signature all has the link , so amazing.
Check this thread https://bitcointalksearch.org/topic/forum-rankspositionsbadges-what-do-those-shiny-coins-under-my-name-mean-178608. This will explain the rankings and the signature you can wear. There are new rules implemented regarding ranking up and only members and up can have links in their signature. Avatar is only applicable to full members and up.
Pay attention also to merit system. This is required for you to rank up. Check this thread for an explanation. https://bitcointalksearch.org/topic/merit-new-rank-requirements-2818350