Or you may use 3 separate dropdown lists to capture the time, as shown below: 

TIme Picker is not available in OOTB AEM. You need to customize the datepicker component and change the type property of the DatePicker. Also, check for valueFormat property for achieving the desired format. type can be defined as: type(string) = date < date, datetime, time By default, it is date. c...

You may refer to the following sample for the same:https://experienceleague.adobe.com/docs/experience-manager-65/forms/customize-aem-forms/dynamically-populate-dropdowns.html?lang=en 

Time picker component is not available in Adaptive Forms. If you want to capture the time of submission of the form, then you may capture the same from <afSubmissionTime> tag in the submitted form data, as shown below.  

Please download it from here: https://drive.google.com/file/d/1dDQSntwrY2dJjH1STlIxOhwtyzxz_69e/view?usp=sharing 

You are trying to run GUI mode of Configuration manager which requires DISPLAY to be set on Linux machine. You need to set X11 DISPLAY before running this, or you should run configurationManagerCLI.sh for CLI mode. For CLI steps, please refer to 8. Appendix - Configuration Manager Command Line Inter...

Not sure what you are doing with your form. Anyway, I have fixed this as well.Fixed Form: https://drive.google.com/file/d/1R8vEWeyIk_hqhC653vOYYiuAdBdncCz9/view?usp=sharing 

Can you refer to this to configure the same:https://aemgeeks.wordpress.com/2017/09/28/gmail-as-your-smtp-server-in-aem/ Please note that you need to use your actual account credentials as username and password.

Yes, you should be doing this by adding a button to trigger the scripts only for once. This will not impact the performance of the form.

Why you are using the .presence? Presence is used to set the object’s visibility. Also, presence can only be set to these values: Reference_Syntax.presence = "visible | invisible | hidden | inactive"Not the ones you are using.Also, .value won't work in JavaScript. you need to use .rawValue, as below...