I mean another address in the same wallet.

Is there a general interface that lets me sign any message, with any address that's in my wallet?  The only interface I've seen is in Chat, when the bot sends me a "Request to sign" message, and clicking on that doesn't let me pick the address used to sign it.

I guess a workaround is to send everything to a single address, but I'm surprised that there isn't a general message signing interface.

For the weekly draw, the bot wants me to sign a message confirming that I own an address.  But when I click on the request to sign message, it signs it with a different address (I have bytes in 2 different addresses).  How can I sign the message with my other address?

In case anyone else was having problems with Coinomi for BTX: they fixed this problem about a week ago.  The issue was that their server wasn't properly handling segwit BTX transactions, so if you received BTX from a segwit transaction into a Coinomi wallet, it wouldn't show the transaction and wouldn't update the balance.

The Electrum server at electrum.bitcore.cc seems to be down now.  Is someone working on that?

Also, the .zip and .tar.gz files at https://github.com/LIMXTEC/electrum-btx-claim/releases seem to be missing the wallet.py change.

For another way to send BTX from Trezor, without using Electrum but still without exposing your private keys, I posted instructions on reddit a few weeks ago: https://www.reddit.com/r/BitcoinAirdrops/comments/7drt94/claim_bitcore_btx_without_compromising_trezor_seed/dq9tir4/

(But it requires more manual work and a Python script; Electrum is a lot easier.)

One issue with holding BTX on Trezor is that you can't sign a message to register for airdrops (because BTX wallet software uses a different prefix string for message signing than BTC wallets do); the Trezor firmware would need to be changed to add support for BTX message signing.  (This probably wouldn't be hard for someone to add though.)

Also, if someone used their seed words to get their private keys, but has BTX on segwit addresses that they don't know how to import into the Bitcore wallet, here's a way that worked for me:

At https://iancoleman.io/bip39/ use the BIP32 tab, and for BIP32 Derivation Path use m/49'/0'/0'/0 and copy a private key and address (which starts with a 1; this isn't a segwit address yet).

In the Bitcore console (Help->Debug window, Console), type "importprivkey YOUR_PRIVATE_KEY test false", then "addwitnessaddress YOUR_1_ADDRESS". That should give you a segwit address starting with 3.  Repeat this for other addresses.  Then close the Bitcore wallet and restart it with -rescan which (after a few minutes) should make it see previous transactions to your addresses, and you can then send from them.

Yes, that's what I meant.

The 1 BTX didn't seem to go to ALL registered addresses; I have a registered address with 0 balance, and it didn't receive the 1 BTX today.  So maybe it went to addresses with non-zero balance, or maybe just to addresses that had at least 1 BTX as someone else said.

Coinomi isn't working properly for me either.  It worked last week, but recently it's not updating the balance (and after I did a Refresh it just shows 0 for the balance), and it doesn't show a transaction I received yesterday (but strangely it does show the transaction for the 1 BTX that I received today).  Another coin is working for me in Coinomi (and the cryptoid.info BTX block explorer shows my proper balance and transactions), so the problem might be something specific to Coinomi's BTX server.

The problem seems to be that I used a Bitcoin wallet to sign the message, not Bitcore.  They give different signatures, I guess because Bitcore's strMessageMagic in validation.cpp has "BitCore Signed Message:" instead of "Bitcoin Signed Message:".  (And I don't think it's possible to convert one signature to the other, but someone please correct me if I'm wrong.)

Could the airdrop registration be modified to accept both types of signatures?

The issue is that my private keys are in a Trezor, and I'd prefer to have my Trezor sign the message, rather than exposing my private keys or moving my coins to a different wallet.  (The Trezor can sign transactions to send BTX without modifying the firmware; but for signing a message, the firmware is hardcoded to use the "Bitcoin Signed Message:" prefix, so it can't be used for registering for the airdrop.)

Is the airdrop registration at https://bitcore.cc/airdrop.php currently broken?  I get "Error: BTX public key (your address) or signed message not valid" even though my signed message is valid (I have done similar message signing for Byteball, which worked fine).

The website says "Address (public key)" which is confusing, but it just means an address, such as 1C8BRHdqCuKwm8ZLmFhiFM3FyFJPyAkRdj, right?  (That's not my address, just an example; and my address has more than 1 BTX on it currently, though I don't think that matters.)
And the message to be signed is just "AIRDROP" (without the quotes), right?

Partially answering my own question: at least in the payout I got today, one of the inputs was from newly-generated coin from the same block.  So I guess the answer is yes, though I don't know if this behavior is guaranteed.

Do payouts from slushpool come from a recently-mined block?  I'm wondering if this could be used to get coins guaranteed to be from after a fork, to mix with the rest of my wallet for replay protection.

What was "Conical Frustum @ 200 10281"?  I don't see where "aP" comes from.

I'm guessing it's related to https://en.wikipedia.org/wiki/200_Liberty_Street

13 and 16 I think you made an obvious mistake.  11 seems wrong to me too.  For 4 I picked uppercase, but the clue isn't clear.  Not sure about 8,9, 22,23, 30,31,32, 45,46, 49,50,51