it's hard to summon any motivation to get eyeball deep in dense Hebrew esoterica without knowing what tasty bits i'm looking for

This is true of any mystical-contemplative tradition: Hekhalothic (including Celestial Jerusalem), Merkavaic, Kabbalistic, Apocalyptic, Hesichastic… In a way the "tasty bits" are the whole of the tradition and you have to attack it as you would any other very large meal: a bit at a time. What you should be looking for is what I'd call a theography, that is, not an explication of the nature of the divinity itself (as in theology) but rather of the experience of unity with divinity, beginning from its first unfoldings and ending with a more or less personal eschatology of its last re-enfoldings, be them purely internal or subjective (as in, the personal enfolding of the mystic-as-god) or rarely as a speculative account of the end of times (particularly in Lurianic Kabbalah.)

That said maybe your questions have narrower answers:

1. Beyond what I wrote above, namely a theography inscribed in a particular tradition, the emphasis on a hierarchical and combinatorial system of analogical correspondences between the immediate sensible world and the transcendent. That is, a system of correspondences linked by symbolic, not causal analogy (a system of metaphors if you will) which vary or are refined in their denotation according to a series of hierarchically organized classifiers (the "worlds" or "haOlam".) These correspondences are combinatorial in the sense that there are generative rules for combining smaller correspondences into larger correspondences, usually along lexical lines: "this" corresponds to "that" if the name of "that" is related by a lexical function of the name of this. This in turns opens to a conceptual ontology where the "natural" or common-sense ontology is taken modulo the equivalence classes induced by those correspondences. For instance, a Kabbalist would say that Moses's serpent "is" the Messiah because the Gematria of "nachash" (serpent) is the same as the Gematria of "meschiach"
2. That the divinity proceeds by symbolic linguistic processes, for one. Reading the first few pages of the Sefer Yetzirah would make that clear: it is a letter-by-letter exegesis of the first chapter of Genesis ("bereshit", "in the beginning" or more literally "it heads with".) That the acts of the divinity and their structure are intelligible not in causal but in analogical terms ("X is Y" wherever X and Y are linked by arithmetico-lexical relations.)
3. It allows you to avail yourself of the divinity's tools of unfolding and re-enfolding. In particular it lets you become a full-fledged co-creator by harnessing the power of the creational syntax
4. In my opinion because there is demand for analogical thinking that is neither completely poetic (where what only matters is the emotions stirred by the juxtaposition) nor completely totemic (where what only matters is the technic or praxic results enabled by the juxtaposition.)