Re Tether-Bitfinex-washtrading, the paper trail indicates that Bitfinex and Tether have the same controlling interests. Dividends aren't the deciding factor - figuring out how both businesses can generate income (Tether via issuing unbacked USD; Bitfinex by driving real volume via pretending to have fake volume).
Unlike the issue of unaudited bank accounts, the wash trading issue isn't as easy to point out, since it requires (a) knowledge of trades taking place behind a black box, (b) high volumes capital to test these trades that requires sending that capital to these exchanges you're skeptical of.
If not, then you should definitely not let British Virgin Islands based Bitfinex hold them either. Use less risky options based in USA or EU, so you are at least protected by a decent legal and regulatory system.
«First, I know of at least one instance where it appears that a wash trade was not charged a fee for a trade.»
Absolutely zero evidence is provided. Just the author saying "trust me, I've seen it."
«Second, even if a fee is charged, that doesn’t mean a wash trader paying fees is really paying fees. If you’re a shareholder in Bitfinex, you’re allegedly paid dividends.»
This is mathematically false. Even if you hold, say, 10% of the shares (huge shareholder) you will still lose ~90% of your fees.
That's it. It's a thousand+ words post with ZERO evidence of massive wash trading.
The rest of the post is just ramblings on unrelated things.
I don't disagree there are shady/unethical practices occurring at Bitfinex, but wash trading is not one of them.