Unfortunately, I am not qualified to comment on how best to support and troubleshoot a Stripe Payment Gateway

The Stripe Gateway isn't really a problem - it can only do three things. 2 are normal behaviour and one is an error which I handle in the module.

It's the way my module handles errors that I am concerned with and I feel I am doing it a sensible way. I was more wanting to check that there wasn't a "better" way that I had overlooked and I am now satisfied that the way I've approached it is sensible and useful to anyone losing my module.

The 'errors' are more 'failed validation' of user input than true errors. So, if the user provides the right data and Stripe doesn't return an HTTP error then there is nothing to report other than success...