score:7
I don't think anyone can give you a percentage, because it is based on suspicion of the individual, and also because security agencies do not release such information. However, I have visited Israel a number of times, and in my experience, TLV security has been significantly easier and more rational than security at major U.S. airports or at LHR. Especially departure security (as opposed to Customs on arrival) would be unlikely to hold your laptop. Given that you are part of a tour group of German citizens, it seems unlikely they would suspect it was an explosive, and even if they did, they'd ask you to turn it on, and possibly examine it further, but there would be no reason for them to seize it. Sometimes, Customs agencies in any country might seize a laptop or cell phone in order to examine the contents if they suspect a person has illegal material (e.g., child p**n in the U.S., banned political material in countries without political freedom), but that happens on arrival.
Upvote:-1
How likely is it for oneβs laptop to be withheld due to security reasons, meaning Iβll have to board my plane without it?
From the limited experience of myself and my friends - this is extremely unlikely, since what is much more likely to happen is for them to detain both you and your laptop... That is, Israeli airport security has a tendency to detain people, and I'm not aware of a tendency to detain people's devices.
But just to clarify - this is not an authoritative answer in any way.