On a purely practical level, if you get off in Zurich and, critically, tell the airline (which I guess will be LX) you won't be continuing to Rome, they will haul your checked bag from the system and eventually it'll get delivered to you - although it could take a while.

If you just fail to board the flight it is possible, even in Europe and under certain circumstances, that the bag will travel onward without you - and then you'd probably be responsible for retrieving it from FCO.

That's why HBO is by far the best answer.

Personally I suspect - given the shutdown in Italy and the number of airlines cancelling flights - it is extremely likely you'll be offered an option to terminate in ZRH anyway if your travel is in the near future. Given your background, and even with my reasonably cavalier attitude to travel, in your position I would not consider it sensible to visit Rome.