A: Dear Ian. These flows are not comprehensively described nor clear enough and there are a number of assumptions or requirements to be covered. That said here are quick feedbacks:

Create automated Store in Messenger: This I do not understand yet what it means but this looks like a big project and RTILA alone may not be enough as you need a user interface and other things

Automate Payment Gateway: If you are using static payment links or buttons like those from Stripes this could be doable with RTILA but still RTILA would need to read the amount/data from somewhere to create the links.