Hi Sue,
Q1) Are there any ways to define a form using python or similar scripting?
No. Currently, you have 2 options to create a new survey: i) within the Survey123 website, or ii) using Survey123 Connect.
Q2) Any plans to be able to define the choices for the questions (select one or select many) using a list from an external database (such as feature class domains)?
To clarify, feature class domains are a property of the geodatabase that the feature class resides in. They are not stored as a list, but within the geodatabase schema.
Please submit your enhancement: "the ability to define choice options for select questions in a survey from a external list" on the Ideas forum: https://community.esri.com/community/arcgis-ideas
Hope this helps,
