Mightn't it be cheaper to order the Lego on Amazon or similar and have it delivered directly to Israel?
With giftwrap option if desired.
Either way the recipient might end up paying import duties in Israel. But for you as sender it might be cheaper to order from the source with the lowest incremental cost.
With which driving license? Jokes apart, Driving a Swiss plated car to Germany with a German license may be illegal as the car Insurance may not Cover You (there are disagreements at the Political Level between EU and Switzerland and they trickle down to this).
Anyhow, if you bring closed Package the Customs will Think you are trading Thema and try to Charge You.
But you can claim they are Gifts for your immaginary family in Germany, or for the Driving license office in Germany, if the value is less than the maximum value you can import without declaration (60€?300€? I don’t know)you are all set.
Interesting what you say about the Plates, I asked both in the VB Düsseldorf and the Insurance and both said Drive where you want how you want and any Plates issue is between you and the local VB.
Can a German licence holder drive a foreign car in Germany? I remember I think that a Swiss licence holder can only drive a Swiss registered car in Switzerland - or am I making that up?