1) Let users exchange USDT for USD no matter the denomination or status. If they can't do that, remove the thing that says "You always have 24/7 access to our balance" from the website marketing.
2) Release an official audit (that doesn't say "this is not an audit")
3) Explain the large amounts of Tethers being minted. If they are legitimate, who is pumping $100m into Tethers almost every 3 days? No need to be specific, but records would be nice.
4) Tell us who their banking partners are that are holding the USD.
5) Put their transparency page back up [0]. Bonus points if they actually keep the "Shareholder Equity" number negative in the interest of transparency, or explain why it might have gone negative.
[0] Compare: https://archive.is/6os3c https://wallet.tether.to/transparency
The fact that they haven't done any of these heavily imply to me that Bitfinex and Tethers are a sham operation.