Document is not old .. libs is the new path where OOTB workflow email templates are present, though we can move it to etc or conf folder and then we can modify them.Workflow Notification Email Template resolution occurs in the following order:/etc/workflow/notification/conf/global/settings/workflow/...

Including in CFM dialog  COmponent with multifield 

Create a component with multifield first according to the requirement.Then include that multifield in content fragment model dialog using sling:resourcetype (granite/ui/components/foundation/include).And in path property give the path of multifield created in above component. This will include that ...

similar thread https://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/uber-jar-6-5-6-apis-jar-is-missing/qaq-p/389706Alternate solution could be you download from maven central repository and upload in your organization nexus repository.There might be ways to do this, raise a requ...

Check the below options:-https://github.com/hashimkhan786/aem-groovy-scripts/blob/master/modifyProperties.groovyCheck the Example 2 in below referencehttps://labs.tadigital.com/index.php/2018/12/18/groovy-script-in-aem/ 

Did the user have access to create Workflow launchers, check the permissions of the User.Try creating the launcher in Vanilla AEM instance.This seems the permission issue, if permissions are fine check the logs get more details and provide it here.

See this related thread. It explains enabling annotations in custom componentshttps://experienceleaguecommunities.adobe.com/t5/adobe-experience-manager/enabling-annotations-in-custom-components-touchui/qaq-p/198320 

which version of AEM you are using . Check the compatible AEM version with core-cif components https://github.com/adobe/aem-core-cif-components/blob/CIF-1181/VERSIONS.md 

You can add your custom groups in OOTB "content -authors" group. Required permissions will get apply to your group as well.

Check the permissions of your custom group.Try adding your User in OOTB group provided in AEM like content-authors etc. If that works then the issue is with your Group.You can make your custom group member of other OOTB group provided.