-->. Yes. Seems to be it wasn't the market.
2) This RNA #coronavirus mutates really fast.
-->. This isn't all that accurate. Fast is a relative term and Coronaviruses have a proof reading sub-unit in their polymerase so they're transcription is much less error prone than a retrovirus.
3) 🧬 has unusual middle segment never seen before in any coronavirus.
-->I've heard this stated but am not sure which scientific article provides the data or what is meant by "unusual middle segment".
4) Not from recent mixing.
--> yes, no signs it is recombinant. It's related most closely to a bat virus found in China.
5) That mystery middle segment encodes protein responsible for entry into host cells.
-->. Not sure about this but am sure that it uses the same surface protein, ACE2, to infect cells as other Coronaviruses. ACE2 is expressed highly in lung capillaries, hence the respiratory effect due to infection.