No, the adverb "too" shouldn't always be set off by commas. It should be in the particular case of the sentence you presented in which it is used in the sense of "also" or "besides": "Apart from being autobiographical, the book will tackle, too, the role of luck in a person’s success." The same should be done to the adverb "too" (but only with one comma before it) when it is placed at the tail end of the phrase it modifies in that same sense of "also" and "besides," as in "Yemen is being wracked by violence, too." (In colloquial speech, though, the brief pause represented by that comma is typically no longer supplied, although this doesn't mean that it's no longer grammatically required.)
However, the adverb "too" shouldn't be set off by commas when used in the sense of "excessively" or "very," as in "The problem is too serious for his small mind to solve," and likewise when used in the sense of "so," as in when the declaration "We didn't bungle the job" is answered by "You did too, and how!"
