How are you calling the servlet? What parameters do you pass to the servlet? You will get workflow session in the execute method in a workflow process but you might not get it in a servlet.Why not pass the wf model as a param to the servlet?

I suggest you to turn on debug in dispatcher logs and check why the dispatcher filters are blocking the request.

Is the parent component a container component? Refer this for including a component inside another component - https://medium.com/@arunpatidar26/cq-iscontainer-property-in-aem-94e5318e04fa 

If you are looking to search or pull up a report based on the audit log events, I recommend using https://adobe-consulting-services.github.io/acs-aem-commons/features/audit-log-search/index.html 

To reduce the impact while upgrading, do the following : List down the ACS Commons features which are used in your project.Make sure the cloud package of ACS Commons is used.Take a backup of environment before installing, so that it can be restored in case of any major issues.Validate the features i...

How are you referring the video URL in the HTML? Can you paste the HTML code?

I recommend using netcentric ac tool for the same. You will have to apply read permissions on folder level and for the children, you can give the necessary permissions needed.https://github.com/Netcentric/accesscontroltool 

Which tool or method are you using to apply permissions?

Some resources from Adobe docs are below -How components are being loaded? - https://experienceleague.adobe.com/en/docs/experience-manager-65/content/implementing/developing/components/developing-componentsHow the clientLib works? How dependecies are being loaded? - https://experienceleague.adobe.co...