Module development and code questions

Displaying SQL stack trace on front end page during security scan

Detailed stack trace-

Introduction: I was struggling with slow ajax requests in a custom module form.  Since I couldn't find any good resources I wanted to share my solution.

How can we avoid displaying sql stack trace on page

SQL stack trace on page-

Security scan trying to manipulate form_build_id value to something else

e.g 

form_build_id manipulated from: form-i0JR1J8PhobAlL1_m6CQ8oHm02Ogf5Z-Gfd9XClh5PU to: form-i0JR1J8PhobAlL1_m6CQ8oHm02Ogf5Z-Gfd9XClh5PU%a5'%20having%201=1--%20

manages to produce sql stack trace on page (UI) showing details of Drupal's SQL entities/ tables

e.g.

I got an error after upgrading SMTP to 8.x-1.0, which caused smtp to fail to send mail. The error is as follows:

SMTP CONNECTION

SMTP module is enabled, turned on, but SmtpConnect() returned FALSE.

How do teachers solve it? Thank you!

In a content type, in addition to various fields, I have 4 numeric fields. For each single field I call the same callBack to perform a check. Is it possible, inside the callBack, to know which field has recalled the callBack?