The rental property definitely belongs on a nonresident CA return. The rest of it depends.
You said your husband was self-employed in ID but performed work for a CA client. Did he perform the work in CA or in ID? If he performed it in ID, even if for a CA client, it is only taxable in your home state. If he traveled to CA to perform the work, he would be taxed on the amount he earned in CA. He would allocate his self-employment income based on the days worked in California and the days worked in Idaho.
The 401(k) contribution would be reported as part of your federal AGI which impacts your California tax. However, it would not be reported as California sourced.
@iping22
