First of all, thank you so much for taking the time to give me your feedback.
1: I understand your concern in terms of google auth. I always refused to implement it because i did not want google to have information about my users, but every developer told me i was missing out on so many signups, so i tried it this time. Now it hurts me to see that a potential customer walked away.
2: In terms of the actual invoice, I will implement this instantly.
I hope it will be good enough one day for you to give it a chance. I appreciate you a LOT.