I'm currently all in tether... which isn't a good idea currently IMO.
You got that right. Bitfinex and Tether are both skating on thin ice at the moment. I don't go anywhere near USDT. Another big bank account seized or adverse actions from regulators could cause prices to skyrocket against USDT.
I'm at Bitfinex at the moment, however I'm thinking of going back to Binance; giving me more options for stable coins.
However, the liquidity of TrueUSD and USDcoin - on Binance, is pretty poor....
Which leaves..
a) a btc only exchange such as Bitmex
or deribit... 
(which is not for me, way too much stress having to keep a constant eye on the market. I like to take time out as needed)
b) Coinbase and legit Fiat. However - coinbase has high fees and very bad liquidity (I have the choice of euros or pounds there.. no dollar
)
However, the liquidity of TrueUSD and USDcoin - on Binance, is pretty poor....
Which leaves..
a) a btc only exchange such as Bitmex
or deribit... (which is not for me, way too much stress having to keep a constant eye on the market. I like to take time out as needed)b) Coinbase and legit Fiat. However - coinbase has high fees and very bad liquidity (I have the choice of euros or pounds there.. no dollar
)Yes but I've definitely noticed liquidity on Binance's USDC market improving. Your best bet may be to spread your liquidity through multiple markets including USDC, PAX, TUSD. If not enough, then you may need to hold BTC and hedge on Bitmex. You could also try Kraken for straight up fiat trading. They have SEPA funding and a much higher volume EUR market than Coinbase. You can probably use their USD market as well.