I'm by no means an expert, but I have been using 7Sage since December. Don't feel discouraged that there are still many problem sets you cannot do. Personally, I think it is perfectly okay to move on and come back to them later.

The one thing I do believe is important to learn first is the lawgic taught in the LR section. That will be applied heavily in the games section. Going in order can be beneficial but isn't absolutely necessary. Do what you feel helps you the most.

But to answer your question, no you do not need to do every problem set before moving on. I would actually advice against it. I would do 1 or 2 sets and move on, coming back to the rest later on when I was ready to practice some more.

At the end of the day everyone is different and you will find what works best for you.

I hope this helps!

Commenting to follow the post However, I am in a very similar boat (I'm scoring at 166 and am shooting for 170). My current plan of attack is to keep reviewing and taking practice tests, since there is no obvious trend to my incorrect answers. I'm hoping that just more practice and repetition will get me there.

For studying purposes I personally believe that the older PTs serve just as good a purpose as the newest ones. The format and techniques are the same throughout. I do think that 6hrs a day will put you at an extremely high risk of burnout, but everyone is different.