On "The Story," Judge Napolitano said any of those options would be a bad idea for the president because he cannot know what Mueller's team knows and what evidence they already have.
"One lie or one close-to-a-lie about a material matter and he's facing a potential indictment," he explained.
He said that FBI investigators are "very, very good" at trapping people, and Trump should avoid falling into such a trap by declining to submit to an interview, which he is legally entitled to do.
Did he also say that no prosecutor would resort to a sworn affidavit or submitted written questions (as the responses would be just the lawyers speaking)?
Given that rock and that hard place, it would seem that the grand jury subpoena (after much legal wrangling) would be the absolutely unacceptable (from the defense perspective) last resort that would make them submit Trump to a live deposition (with some limits, no doubt). One theory is that trying to smear Mueller now will allow Trump's team to cry "witch hunt!" when Trump refuses to testify to a grand jury (thereby affirming his standing with his 30% support).
"i disagree with your analysis [or judgment], nevertheless you have the responsibility of moderating this board so i honor your authority to make the moderating decisions."