Sam2- that is what I meant buy going too far. marrying a non Jewish woman or even moving in with a non Jewish woman with an agreement (even de facto) of being in a “permanent” live in relationship. It was just too hard to write it out so I said “going too far”. If one marries out then one is supposed to sit Shiva. I heard this psak from a few Gedolim who were issuing the ruling as Halacha Lmaaseh
Naftush- One can set up a trust in US law and stipulate whatever he wishes… he can say that the money can only be used to buy cars for people with blue eyes. He can stipulate that only college grads can benefit form this trust and he can stipulate that only Shomrei Torah Umitzvos can benefit. It is not regulating from the grave. It is a valid legal trust with specific structure and direction.
In halacha one can give a conditional gift and so one can say that they give child x 100G if he keeps Toarh and Mtzvos (req definition) for 3 years…….. or whatever.