> Does it mean that there is still no way to do that? Really no way? :(

No easy way. A hard way it to drop them and then create them again.

>> Foreign keys are exceeding valuable semantic information
>> about a database, but ...
>> sometimes it is catastrophic, as when a restore discovers
>> a violation.
>
> That's my case, and it may well prove catastrophic...

gbak has a switch that allows to restore database without validity checks.
In your case, your application should do something similar...

>> Triggers, from the afternoon when I created them,
>> have had the ability to be marked inactive.
>
> How can you disable triggers, by the way?

ALTER TRIGGER <name> INACTIVE

Roman