if you what anything to share please do for me and others to read in one place

What you want, shared, read somewhere.You talk about "taboo" meaning and the true meaning of taboo is broad,
if there is talk on this forum I can interpret:
I think you should respond to his full sentence. He's not asking about taboo per se but 'exchanges taboo'. Your reply is nowhere close what OP wants to discuss about.
- Wash trading, check!
- Insider trading, check!
- Scamming, check!
- Fake volume, check!
- Fake deaths, check!
- Mt. Goxxing, check!
Additional activities that some exchange might do:
- Selling user KYC data.
- Selective scamming with KYC.
- Doing fake ICO to gain additional BTC (Yobit?).
- Terrible ToS, only protect the exchange but no real help for the users (like having a rule where a user should not post their issue publicly and instead have to chat the support, because if they do that then their funds or account will be locked).
- Allowing deposit but blocking withdrawal.
- etc.