Is there a lighter form to use the HTML source code with?

Currently, the code provided is extremely heavy on javascript.

Is there code I can remove?

It's not possible to have a lighter version of the source code of your form. But you could remove the JavaScript and CSS scripts and resources keeping the form only, this should still work as long as you do not change anything of the form HTML attributes nor the field's names. 

However, please note that you will lose the style and all the functionalities so your form will look totally different as it looks on the Jotform hosted version, the submissions should be recorded on your JotForm account always so you can access them by logging-in into your account. 

Also, note that each time that you make any update to your form through the form builder, you will need to update the source code. Changes made to the embedded version will not be reflected on the form builder either. 

If you have any question, please let us know.