People will make bad decisions and societies in general will fuck up, but that is part of the process and voters will adjust accordingly.
Methodical and sound polling on a single issue routinely comes within %'s of actual votes. Yet there are numerous issues overwhelmingly favoured in society which politicians knowingly ignore.
Those are mostly pretty easy questions.
For driving and working high, it's just the same as working or driving in any other impaired state. It's slightly trickier than alcohol because it isn't as easy to measure the level of impairment, but that's also true of many prescription and probably even some over-the-counter drugs, so it's not a new problem.
For all of the other questions, you could just copy the rules for tobacco verbatim and end up with a workable set of rules.
Straw man in the wild. Nobody here advocates direct democracy on every issue.
However, one simply can't argue that a government that acts against the interest and preferences of 90%+ of the population it supposedly represents and serves is doing a good job.
>Furthermore, legalization of cannabis requires more...
You speak of these questions as if they haven't been answered already in several countries and multiple states in the US.
And in any case, this is another strawman. The problem is not the slow rate of legalization, it's that the Federal government is not moving at all towards that goal (in particular, by keeping marijuana on Schedule I), when simply letting the states regulate the issue would have satisfied many people.
I'll bite the bullet and say that it can, in some specific cases. "Acting against the interests and preferences" of someone has a magnitude, it's not just a yes/no question. A governing system that mildly inconveniences 95% of the population to safeguard a vital liberty for 5% is doing an excellent job, IMO.
I don't think there is much incentive to build such systems now outside of say voting systems for user feedback/issues on product systems (which also have lower barriers as for the ultimately philosophical issue on deciding who is allowed to vote, and face virtually no push back from those who benefit most from the incumbent systems).
Although admittedly, I'm not as well-read as I'd hope to be, so take this with a grain of salt. But the way the media I've read has portrayed marijuana in Canada has been "Pot's legal in 1 year! ...okay, how are we going to implement this? [provinces rush to come up with plans]"
Furthermore, legalization of cannabis requires more than just saying "okay, it's legal now". There's a ton of unresolved questions: what are the rules around driving high? Who can buy cannabis legally? Which jobs are allowed to be worked high? Which businesses can sell cannabis? What license do you need? What are the penalties for flouting age restrictions on sales? Can you smoke cannabis in a bar? Can you vape cannabis in a restaurant? How is cannabis taxed, and at what rate?