I'm not sure whether to give the quick explanation to that or the proper one - an in-between one is that the income idea won't work because there is no guarante

I'm not sure whether to give the quick explanation to that or the proper one - an in-between one is that the income idea won't work because there is no guarantee that e.g. my health will continue OK for twenty years or that my job will remain steady. There would not be the equivalent of an income protection scheme available either. There are simple methods available in principle based on the real rental value of the home and treating the buyer as a form of renter but in reality all the so called 'islamic' schemes do not actually involve risk sharing and consequently it's hard to be sure that they are indeed 'halal'. BTW on your first point it's Ramadan so if I do lose my patience I've blown it....:-)