This list of questions seems to have two obvious purposes and one sneaky one.
The obvious purposes:
To get Trump to provide evidence against himself which Mueller’s team has failed to gather from other sources. Obviously, Trump should not answer questions with this purpose.
To get Trump in a perjury trap in which his answer disagrees, if only slightly and arguably, from an answer of another interviewee, in which case Mueller will proclaim the other interviewee to be obviously telling the truth (even if that “truth” was obtained in exchange for immunity or a light plea deal) and claim Trump has committed perjury. Obviously, Trump should not answer questions with this purpose.
Alan Derschowitz proposes a sneaky angle to the questions: That they have been constructed to not be answered by “Yes” or “No,” but have been constructed to invite open-ended answers and digressions, to encourage Trump to ramble on and wind up talking about things not even asked about or even much thought about, for which they can then charge him with perjury.
Trump is a rambler, and his mouth often seems to be an independently-acting organism with full autonomy of action and little guidance from his brain.
Given that this is obviously a set-up, and that the Special Counsel’s office is acting unethically even by leaking these questions to its partner-in-crime the media, Trump should just invoke any privilege not to answer, from the Article 2 separation of powers to executive privilege to “any other privileges I may enjoy” (a method of invoking the 5th Amendment without saying “I invoke the 5th,” which Democrats employed during previous investigations), and tell Mueller to go spit.
Derschowitz himself argues Trump should answer the questions in written form (with full vetting by his lawyers, one presumes), or, if that is rejected, then he should negotiate for a certain number of questions or a certain time limit for questioning. He also allows that Trump can/should invoke Executive Privilege, but not the 5th Amendment.
I disagree. Others have been permitted to allude to the 5th Amendment without specifically invoking it, just generally asserting “any other rights I might have under the Constitution.” If it works for Democrats, it works for Trump.
Meanwhile, Paul Manafort’s legal team says that Mueller’s team has told him they have failed to find evidence of any contacts between himself and Russian officials.
At least that’s what the Manfort’s lawyers say that Mueller’s lawyers say. Who knows with these people what the truth is.
In any event, the Deep State has declared war on a duly elected president chosen by the people in open defiance of their demands, how dare they!, and Trump should not refrain from declaring war right back.