Which ITR form is to fill?

1. If insurance commission is the regular and forms part of the major source of income then ITR-3 is preferable. 
2. If the insurance commission is part-time and does not constitute a major part of your time and effort then ITR-1 would be enough. 
3. In the case of ITR -1 both insurance commission and interest income from the bank should be shown under Income from other sources. 
4. In the case of ITR-3, it should be shown under the head business income. 
Please correct me if the above solution has an alternative view.