For the first question: do you mean to create multiple copies of the first page at design time or after rendering the form? At design time you can add new subforms and fields to design the form or copy/paste the existing component available on the form. or Use the instance manager to repeat the subf...

For GDS, you must make sure that the directory is not located at the root of the drive but is located in a subdirectory. For example, the directory should be D:\GDS and not simply D:\.   Only the administrator account that is used to run the application server should have read/write access to the GD...

columnWidths property helps to set the width of the column dynamically.   https://help.adobe.com/en_US/livecycle/10.0/DesignerScriptingRef/WS92d06802c76abadb-3e14850712a151d270d-781a.html

If there are multiple selections for the sub-dropdown for some value in the first dropdown, then you need to take the sub-dropdown in the form. You can place the sub-dropdown in place of the text field you are putting in the form. You can have both dropdowns visible for the selection, I don't unders...

The below link has your answer:  https://experienceleague.adobe.com/docs/experience-manager-65/content/sites/administering/introduction/tc-msconf.html?lang=en    

Refer to the below to give proper privileges and roles for your user group to work with the template and forms. https://docs.mktossl.com/docs/experience-manager-65/content/forms/manage-administer-aem-forms/forms-groups-privileges-tasks.html?lang=en  

Have you copied and pasted the content from somewhere inside the short description field? It seems like taking the rich text. Try to remove the whole text and then type a single word and check. Take a fresh field and add a single word in short description to check.    

You need to write the code to dynamically populate the second dropdown on the change or exit event of the first dropdown. eg.: Need to create the mapping like the first dropdown has the country and the second dropdown has the city for that country.   India > Mumbai, Delhi Australia > Sydney, Melbour...

Seems like an issue with your data binding in the table row, need to check your form with sample data to resolve the issue. Share form and sample data if you can.

With another tool, I don't know if it's feasible or not, but if you want to replace some code then you can open your form in AEM Designer and go to the XML Source tab, where you can find and replace any script code.