How to hyphenate "non self destructive"?

The Chicago Manual of Style, sixteenth edition (2010) actually takes three shots at offering a coherent guideline on this point. Two of those attempts are arguably helpful:

6.80 En dashes with compound adjectives. ...

A single word or prefix should be joined to a hyphenated compound by another hyphen rather than by an en dash; if the result is awkward, reword.

non-English-speaking peoples

a two-thirds-full cup (or, better, a cup that is two-thirds full)

...

7.85 Hyphenation guide for compounds and words formed with prefixes. ...

non nonviolent, nonevent, nonnegotiable, but non-beer-drinking

What these two guidelines suggest is that if you would hyphenate self-destructive (and I certainly would), you should attach the prefix non to the compound term with another hyphen.

Bryan Garner, Garner's Modern American Usage, second edition (2003) adopts a similar analysis in discussing phrasal adjectives that begin or end in a compound noun (not entirely on point here, but useful as an illustration of a similar situation:

Phrasal Adjectives...

E. The Compound Conundrum. When the first or last element in a phrasal adjective is part of a compound noun, it to needs to be hyphenated: post-cold-war norms, not post-cold war norms. Otherwise, as in that example, cold appears more closely related to post than to war.

For some reason, Garner doesn't consider the possibility of rendering the phrase as "post cold-war norms" to be worth discussing at all.

The U.S. Government Printing Office, A Manual of Style (1986) reaches the same conclusion as Chicago and Garner, but it takes a different route to gt there:

6.32. Use a hyphen or hyphens to prevent mispronunciation, to insure a definite accent on each element of the compound, or to avoid ambiguity.

[Relevant examples:] non-civil-service position, non-tumor-bearing tissue

The only discordant advice I came across was from Words into Type, third edition (1974), which offers this unusual prescription in situations involving "Compounds with noun plus '-d' or '-ed'" (again, a slightly different case from the one that the poster here presents):

If the first part of the compound is qualified by a preceding adverb, omit the hyphen.

[Examples:] fine-grained sugar [but] extra fine grained sugar

I don't understand the thinking behind Word into Type's guideline, but if I were looking for a justification for rendering "non-self-destructive" as "non self destructive," WiT's coverage is about as close as I could get to an analogous form in a published style guide.

Overall, however, the style guides I consulted seem much more amenable to the form "non-self-destructive."

Reviewing the logic of each of the alternatives that the poster suggested, I offer the following observations:

Non self-destructive: The problem with this option is that it treats non as a standalone word, rather than as a prefix. But if you use the form non-destructive (or nondestructive) to express the idea "not destructive," you are using non- as a prefix; and it's hard to see why that term should suddenly transmute from a prefix (non-) into a freestanding word (non) just because you are trying to express the idea "not self-destructive" instead of the idea "not destructive."

Non-self destructive: The problem with this formulation is that it sounds more concerned with the "destruction of the non-self" than with the "non-destruction of the self."

Non-self-destructive: This is the form I would use, for the reasons discussed earlier in connection with the style guide discussions.