Well, generally if you propose a law like that there is a large discussion around it and those that propose it usually write a whole bunch of 'this is why its a good idea' stuff.
The Bundesrat (i.e. the State Council) sometimes proposes an alternative. So they might say 'Initiative X proposes Y, but the State Council recommends a compromise where we do Z instead'. And then when you vote on it you have 3 options, rather then just 'yes' or 'no'.
There is also a check of the highest court, where they basically say 'this isn't really according to international law'. However that is just a recommendation and people can ignore it when voting.
Also, even if something goes threw, the actual implementation usually slightly adjust to reality on the ground somewhat.