Crime seems to have been put very little consideration into. Crime rises too high, too quickly and can just as quickly and easily be negated by decisions, governors and the free enforcers you get from the capital building. From what I've seen the effects of even maximum crime is quite mild which is has to be considering how quickly it can rise.
Crime IRL doesn't only affect trade, but also affects all forms of commerce and undermines the authority of the government. Why pay taxes to the government when you also have to pay taxes to mafias who offer you "protection" and wants to manage their money through the black market? They both encourage and help in hiding money from the government.
Not to mention murder, thefts, prostitution, rape, drug abuse which has massive societal consequences on stability and the social mobility of the population.
I would like to see crime giving more negative modifiers but also being rebalanced to rise much slowly. For instance you should get events such as black markets that reduces civilian goods generated, mafias that reduces energy credit generation and a lot more pops being stuck in crime related jobs. If crime is 100%, shouldn't that mean that nobody is following the laws which means that a greater portion of the pops are stuck in crime related jobs and you're seeing a lot less resources from the planet as well as low stability?
Crime syndicates should be reworked to see cuts from civilian goods and energy credits being siphoned from the affected civs that they set up branch offices inside and see these effects earlier.
I would also like to see some rework to the strata system with a new "education" mechanic where crime hampers this value and hinders pops from being promoted to the next strata.
In addition I would rather see enforcers and governors giving factors to the crime value of a planet rather than a subtraction, meaning that an enforcer can only reduce the crime value by a percentage like maybe 15%. 0.85^(number of enforcers) so 20 enforcers would reduce crime value to approx. 3%. For my capital planet as an example which has 84 crime from pops and no other modifiers, 4 enforcers would reduce that to approx. 43,8 while 8 enforcers would reduce that to approx. 27. Which a crime related governor the value could be multiplied with 0.75 again giving me a final score of approx. 17. By taking away the straight subtraction feature and replacing it with multiplication, we're ensuring that crime always is a factor in all planets and becomes worse with a lot of pops who add crime value to the planet. It also means that the player cannot eliminate crime through enforcers alone, but he can severely reduce it with enforcers. The penalties could show up earlier but be modified compared to the overall crime on the planet so the penalties for low crime is less severe while high crime is a lot more debilitating.
In addition I'd like to see things like crime being able to spread between planets (except for penal colonies), more direct action being taken against crime and criminal pops such as autocratic empires being able to straight up purge criminal pops.