After making Object1 related to Object 2.
You can then add a Related Field in Object1. Obj1 - > Object Definition -> Fields -> New Field -> Related Field.
Also, mark the field as 'Editable in Edit Pages'.
Do this for all the related object fields that you want to edit in Obj1 Edit pages.
After making Object1 related to Object 2.
You can then add a Related Field in Object1. Obj1 - > Object Definition -> Fields -> New Field -> Related Field.
Also, mark the field as 'Editable in Edit Pages'.
Do this for all the related object fields that you want to edit in Obj1 Edit pages.