4) Lets say I have a trading bot (in betting or crypto exchange) and this bot goes wild due to misprogramming and I lose loads of money. Are all these users filling my orders scammers, when it's obvious that these prices are wrong ?
In trading that would be on you, you are trusting your software to make decisions for you. No one is tricking it with a series of commands or events to make it do something outside of designed operation.
I agree with that of course

But lets look at it from the the other side. You see a 10 BTC sell order in a self-regulated exchange for $100 per BTC and you buy them. Would you feel good about it ? Would you consider this behaviour ethical ? If
you don't buy them, then another user will buy them. Would you hesitate to buy them to not have any compunction ?
Does it make any difference, if you actively buy them or just had a order in the market that mysteriously got filled ?
the 2nd and 3rd ones are abuses and should be reported , never seen the 2nd one happening tho
I never saw it for 1X2 and AHC too, but there was for example a bookmaker in the past, where in Formula 1 you could parlay odds for winner & Top3 market. When I told them, they never got back to me and didn't even fix it.