AEMaaCS Forms - best practices

Hi all,

What are the best practices around forms 

if one has a form model connected to data source say CRM

i have data source checked in per the documentation , I have form model based on data source and is not checked in, and I  plan to activate the form(based on form model) itself and not check in the form into repository , 

1. should one Checkin form model connected to data source to the repo  or just publish it along with the form?

2. Does a data source need to be configured to CRM again for publish env as it was to be done for author or is  just source repo Checkin of  data source into repo , that then sends it to publisher is sufficient ? 
3. Using form model submission, the submission id is null in network tab- does it have bearing while the data is submitted successfully ? 
4. any docs on these aspects ?