If an exchange charges fees, it's almost certain (and 100% certain for BFX in the past) that they waive them for certain VIPs and "liquidity partners". Same for selling/giving colo access and other higher-quality data access. (Good luck getting exchanges to publicly admit any of this, though, since it scares off the prey.)
As for spoofing and wash trading... Of course. Chinese exchanges have been notorious for this (seeing 100s of orders making up 80% of book depth out to 10% disappear on 1 tick is amusing), but it happens everywhere and is definitely not a single entity. I would guess that a significant portion of this is related to algo trading and anti-algo-trading, exploiting stupid stuff like MA crossover bots. In general, wash trading is more encouraged than discouraged, since it makes the exchange appear to have higher liquidity.
Lastly, of course, there's all the exchange fuckups and oddities that have been very quietly buried due to financial incentives on both sides, like when it was possible to list arbitrarily large orders that would simply vanish once traded into. There is a long list of incidents that could be added here, some of it public but hard to find and the rest of it too sketchy to ever talk about.
If you get into this stuff without a firm understanding that nothing is real and everyone is lying to you, you're going to have a bad time.
If an exchange charges fees, it's almost certain (and 100% certain for BFX in the past) that they waive them for certain VIPs and "liquidity partners". Same for selling/giving colo access and other higher-quality data access. (Good luck getting exchanges to publicly admit any of this, though, since it scares off the prey.)
As for spoofing and wash trading... Of course. Chinese exchanges have been notorious for this (seeing 100s of orders making up 80% of book depth out to 10% disappear on 1 tick is amusing), but it happens everywhere and is definitely not a single entity. I would guess that a significant portion of this is related to algo trading and anti-algo-trading, exploiting stupid stuff like MA crossover bots. In general, wash trading is more encouraged than discouraged, since it makes the exchange appear to have higher liquidity.
Lastly, of course, there's all the exchange fuckups and oddities that have been very quietly buried due to financial incentives on both sides, like when it was possible to list arbitrarily large orders that would simply vanish once traded into. There is a long list of incidents that could be added here, some of it public but hard to find and the rest of it too sketchy to ever talk about.
If you get into this stuff without a firm understanding that nothing is real and everyone is lying to you, you're going to have a bad time.