I'm not sure about where the upper bounds of legal complexity should be, but I do have at least one thought on how to limit the overall complexity, at least for the average citizen.
Eliminate all victimless crimes in their entirety. If no third party is harmed or unreasonably endangered, there shouldn't be any reason to fine or incarcerate someone. This basically eliminates all 'possession of' crimes that are so often misused by police to inflict all kinds of harm. (Good example being getting arrested for some marijuana in the car leading to car impound and ludicrous fees to get it released.)
I agree, but I don't think that's relevant. Those laws are pretty well known, and their problem isn't obscurity or complexity, its injustice of outcomes.
I disagree primarily due to the way plea deals are handled. You can be innocent of any wrongdoing and still have to take a deal that results in jail time to avoid losing the rest of your life. If there is no charge, there is no need to plea. And, if there is no charge (and therefore probably no arrests being made) there is no looking for evidence of some other thing. (Imagine someone arrested for Marijuana, but it turns out they also happen to have some party drugs somewhere. Game over.)
That said, these laws are complex. [0]This is a felony scoresheet from Florida that shows how things get tallied up. Looking closely you can see the extreme impact of plea deals in sentencing, and the way multiple charges get added together.
The return of mens rea requirements and sharp curtailing of strict liability crimes would solve some of the effect of "surprise laws" at the cost of making enforcement and convictions more difficult - which some to many would call a feature and not a bug.
I'm firmly in the camp that convictions should be difficult to get. I dislike the manipulations of the legal system that universally work against the average person and for the large entities or wealthy who can afford expertise.
Jury Nullification is one such example. Threats of life in prison (even if innocent) unless you plea down to a lesser charge is another.
Eliminate all victimless crimes in their entirety. If no third party is harmed or unreasonably endangered, there shouldn't be any reason to fine or incarcerate someone. This basically eliminates all 'possession of' crimes that are so often misused by police to inflict all kinds of harm. (Good example being getting arrested for some marijuana in the car leading to car impound and ludicrous fees to get it released.)