The author never makes this claim. The argument is not concerned with whether or not there is a reason to believe that alien life exists, just whether humanity will ever find it.

The author never speculates about why scientists won’t find alien life, nor does the argument suggest that scientists need better equipment.

This accurately paraphrases the conclusion: “The dream of finding aliens is destined to remain a dream,” i.e. no matter how hard scientists try, they will never find extraterrestrial life.

The author doesn’t weigh in on the issue of justification one way or the other. Nothing in the argument offers conditions that would lead to the search being justified or unjustified.

The author never makes a recommendation about how money should be spent. Although the author tells us a ballpark price of some equipment, no opinion is offered about whether we should be spending that money.