So can anyone in detail explain the benefits of being a member? so far I know that you get full access of all the skills/items/quests/map/activities and bonus keys for treasure hunter. But as a member do you gain the benefit to gain more experience when you are training a specific skill? like 2x xp rate for members and regular 1x for non-members. Then on some events like double-xp weekend members get 4x and non-members get 2x? In short terms. Does members get 2x xp or nah?
To answer your question on "What are the benefits of being a member?", take a look at What do you get as being a member?
Being a member in itself does not grant double experience, however through various means you can accrue Bonus Experience
Bonus experience is a mechanic which grants members double experience when training a skill. It may be earned through various methods, even by free players. However, free players must become members to be able to use the bonus that they have earned (except for during Bonus XP Weekends).
The remaining amount of bonus experience may be seen by hovering over a skill; it is displayed in green. This amount is the bonus experience, not total experience; e.g., if players have 10,000 bonus experience remaining, they would have 0 after 20,000 total experience gained — 10,000 experience plus 10,000 bonus. While training, experience gains are displayed with the total experience gained followed by the bonus experience fraction of it in parentheses; e.g. if 1,000 total experience was gained and 300 of that was bonus experience, the popup would display +1,000 (300 bonus experience).
Bonus experience underwent a large overhaul with the Treevolution update where a large number of items became almost completely cosmetic and the bonus experience from wearing them became transferable to just training.
The maximum amount of bonus experience a player can stockpile in one skill is 100,000,000.
The sources for bonus XP are as followed:
Single use sources
Time-locked repeatable source
The following sources are repeatable, but only a limited number of times per unit of time; for example they can only be claimed once per week.
Temporary, recurring sources
The following sources are usually in-game for a limited time, but eventually return.