This is all very good advice. I followed EK strategy of "read for the main idea." I also practiced from their 101 passage book. I had trouble timing too, but I did a few things to remedy that.
First, I forced myself to read for the main idea: I would basically summarize each paragraph (chunking, in my head) as I read and then the whole passage after I was finished. This seems like it takes long, but it's just a few words, in my head, about the main idea.
Second, I only look back when it requires it: A small detail, a name, etc.
Third, I answered each question as they were presented. I did not skip.
Fourth, always practice by timing yourself. If you practice the above, you will find that more efficiently you answer the questions, the less you back, and the more effectively you summarize the main idea(s), that you can get done with passages in approximately 8 minutes.