And kindly give advice on how a member can become a DT1 or DT2 member I know it's very hard to become those positions However, some initial steps were suggested.- 
Default trust requires one to be trustworthy and more importantly have good judgement in determining who is trustworthy or not. So, one who desires to be on DT should be able to give good give feedbacks and follow them up, to know when to reevaluate them.The trust system is not one that you deliberately try to get into, as this could cause you to give out wrong feedbacks. Do not chase being on default trust, just act naturally and try to improve the forum experience.