Often times an incorrect answer choice can be eliminated when it describes something that is not discussed in the stimulus. Not here. Even though bacteria which don't have phenazines are not the topic of the stimulus, the correct answer is about those very kinds.

The conclusion states that "often" people portray themselves as they wish to be perceived but the necessary assumption only says "at least some." If "some" is one or more can that be equated with "often"?

What does PSA stand for?

Your lawyer friend speaks truth. I know many a lawyer who joke about the terrible laws schools they attended and who are extremely successful. Also, let me tell you about my lsat journey which began in 2017. I took a PT and scored maybe in the 130s. I then read the powerscore logical reasoning bible and the logic games bible twice. For years, I struggled on the analytical section, but I finally broke into the 150s this year. Just relax and enjoy the ride. I am a firm believer that some of the most rewarding things in life are also the most difficult to achieve. If it were easy, everyone would be doing it.