After saving an Ad it should go back to the Ad list, I don't see any issues with that.
I have made some changes for front-end to display it correctly in the next release. The promo code discount value field is float the min/max invoice is decimal.
Will be fixed in the next release.
Cannot reproduce it but I have made some changes to prevent the error.
Advertisers get an email before it expires and when it expired.
It is fixed already. make sure your are using the latest template unmodified.
My add-on adds the sam_counter template function using the templater_setup code event listener. If you see Function sam_counter is unknown it means that XF has failed to apply it.
In the stack trace I see two add-on that seem to extend the templater class. Try rebuilding those as well...