Is there a particular aspect of the achievements that you find confusing? What type of content do you prefer to play on a regular basis?
At a base level, if you do the main story quests see (like the chapters listed in each zone) and continue to do the emissary quests for reputation, that tends to be a large chunk of the work. Did you have particular concerns about these requirements that we listed before they are playable? I appreciate the input!
Did you watch the recent Q&A that talked about the timing of the Kul Tiran and how it relates to things? We understand that nobody wants to wait but we still aim to deliver the best experience possible and sometimes that leads to delays on things.
One thing to note from your post, what further required content is still inaccessible?
Making a new race like Kul Tiran is a challenge and it did impact the timing of things a bit.
The scenarios are part of the actual unlock process which means the races are playable which is happening in the next content update. I thought you were referring to more requirements to complete which is a different thing. On the bright side, it means more content is coming! 
devtrackers.gg