I think I'm seeing the current block with sat/vbyte ranging from 1 - 146, average 132. What happens to the 1 sat/vbyte TSXs? do they remain 'unconfirmed' or purged?
Purged from the mempool. Note that miners can include any valid transactions that they want and will often include some low fee transaction due to either them being paid or the transactions being their own. Even if the transaction gets purged from the node's mempool, miners who has seen it can still potentially (though very very unlikely) include it in their mined block.
Has this TSX been purged or is that yet to come? mempool says ETA - in several hours or more.
Purged.
If my understanding of the above is wrong please let me know, not sure about posting the TSX ID, is that OK?
Your understanding is on point, you can post the TXID if you want but that'll result in some loss of privacy.
I've never used Trezor's suite but I'll assume that they do not purge the transactions themselves. If you were to use Trezor with some other client, Electrum for example, it should not appear or will appear as a Local transaction and you can remove that and resend again.