Well, not all incoming signals get the same weight for the outcoming signal, as the dendrites are e.g. more or less close to the part of the cell where the spik

Well, not all incoming signals get the same weight for the outcoming signal, as the dendrites are e.g. more or less close to the part of the cell where the spikes are generated. But this computation is just analogous to the connection weights together with the activation function in artificial neural networks. That's not what enables classical conditioning in single Cerebellum cells.