I have very few ideas on how to review an anthology of short stories, so perhaps you guys can give more tips. Such as the answers to: 1. How do you arrive at a judgment whether or not the entire collection is worth reading or not? 2. Do you need to review all the stories in order to prove it? Any help will be greatly appreciated. Thanks.
If you are referring to "review" as in rating a finished body of writing, that isn't the kind of review we perform on this site. We critique with less emphasis on judgment of a piece's overall merit, and with more on how the writing, however good or poor it is, can be improved. You can pretty much forget about submitting an anthology to a publisher if you are an unknown writer. However, to answer your question, to rate an anthology, or any book for that matter, you have to read it all. But if you only want to discover whether it is worth your time to read it, then read it until you decide it is not.