Hello,
I think by using Zapier you could automate most everything as Zapier has the webhook mechanism and it provides most modules you described here: Google Sheet, Shopify, Trello, Mail System, etc. So, in my temporary recommendation is by optimizing your Zapier scripts. Or in case, Zapier has some limitations, you could consider to use Integromat which has more modules than Zapier.
Let me know if you are interested with my methods.
Best Regards,
Khamid