For the E-Mail functionalities, there we had to fix some code at core file, you do not need to edit it again.
However, if you need to change your E-Mail SMTP configuration, please look over .env file at your root directory, at the bottom section, you will find the E-Mail config.
For the maps, we will remove the Google map at future update because of it’s now Paid. but if still now you want, you can use, could you please provide us some screenshot to understand better? take a screenshot which you are inputting, and take screenshot what you are getting the result.
The ad should remove after 30 days from frontend, but if anyone comes with an URL, it should show. If you need any advanced feature, then you need to customize it.