2. Is there a way in Trezor to see the size of each UTXO? Without that info, I have no idea whether a UTXO is dust at this price. I have exported the trezor info into a csv, but that doesn't give me the size of the UTXO.
You can't see this information in Trezor Suite app, but you can turn on coin control, select UTXO you want, and set custom fees double checked on mempool.space.
Try using this UTCO calculator that was made by Jameson Lopp to get more accurate size values:
https://jlopp.github.io/unspendable-utxo-calculator/