Okay I'm thinking a reworked Huluganni for the UU, specifically with a Attack Buff vs open terrain and cities, but with debuffs to defending and rough terrain. It'd encourage the Hittite game to be about attacking your enemies before they can attack you, as on your home turf your UU will be mostly useless, but against Egypt, southern Mesopotamia, Elam, and the Levant, you'll be a force to be reckoned with.
For the UB, I'm thinking of
a Kārum, it'd replace Lighthouses, be unlocked at Property, does not require coast, gains 1 happiness with Iron, but causes 1 unhappiness. It's able to be built anywhere and is unlocked two full tiers early, but in exchange gives 1 unhappiness until you have Iron, which requires a tech of the same tier as the Lighthouse's.
For the UP, I'm thinking the aforementioned first Total Collapse is a Collapse to Core instead would work well not only as a protection against the Bronze Age Collapse, but also as insurance should the player end up unstable. Of course, it can't protect against an invasion so the Persians, Greeks, and Romans would be the main threat to the Hittites.
I'm also thinking that the Ottomans should be a conditional spawn, for what I hope is a very obvious reason.
The Hittite core is the west half of the Ottoman core
