As long as it's a Melee weapon that's compatible with a Martial Arts style you've got, sure.

We don't currently plan to detail it in any of the books we're currently working on, beyond the description of it in House Cathak's holdings.

No, jumping up and falling doesn't count as "moving downward to reach close range."

It discusses what they were, but not in extensive detail.

Yes. 10char

It's not something we've focused on so far.

Yep. They last until you undo them.

There's a lot of factors involved, and I don't really have enough information to make a good recommendation.

Yes, it has.

Abyssals are legendary heroes whose magic evinces the bleak power of death - cruel death, death unconquerable, death triumphant, death that makes your life seem small - and the the iconic magic of the Deathlords.

There wouldn't be a single generic reaction. Coren is noted as keeping her lineage a secret not because she's afraid of what other Dragon-Blooded would think, but because of what her family, a house devoted to hunting down and slaying demons and other Anathema would think.

Solars are resonant with everything, unless an artifact specifies that it isn't resonant with Solars.

Non-Solar Exalted are dissonant with any artifact that doesn't include one of the magical materials, unless otherwise noted.

It'll reference specific materials they import from certain satrapies.

I'm not totally sure what you're asking. They have Ability-based Charms, if that's what you mean?

I find "what can these people do that no one else can" isn't really a useful way of defining them. Like, it'd be impossible to talk about what Lunars do without talking about shapeshifting—but other Exalted can use sorcery or Evocations to shapeshift.

They're so hugely different that it's hard to single out any one main difference. Their concept, their play experience, the narratives they encourage, their place in the setting, their Charm sets, their power level, and their fictional inspirations are all totally different.

I doubt they face much scrutiny from the Order—it's largely applied to God-Blooded to make sure they don't engage in proscribed interactions with their parent spirits, but those largely don't exist for Dragon-Blooded.