For supported MIME types refer https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/assets/file-format-support.html?lang=en If it is not listed here , will recommend to raise a support ticket to adobe. Thanks

A web tier config pipeline Deploys HTTPD/Dispatcher configurations Refer experienceleague.adobe.com/docs/experience-manager-cloud-service/content/implementing/using-cloud-manager/cicd-pipelines/configuring-production-pipelines.html?lang=en#web-tier-config  Thanks

Using clientlib at component level depends upon the requirement .There is no as such fixed rule for this. For more details on clientlibs refer : experienceleague.adobe.com/docs/experience-manager-65/developing/introduction/clientlibs.html?lang=en 

Any changes in dispatcher module can only be deployed via pipeline in AEM as a cloud service .

in addition to @arunpatidar  @DEBAL_DAS   refer https://experienceleague.adobe.com/docs/experience-manager-65/developing/platform/query-builder/querybuilder-predicate-reference.html?lang=enfor query builder predicate reference.

You can set the permissions in repoInit file and push the changes with in build .Refer: sling.apache.org/documentation/bundles/repository-initialization.html   

Refer : https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/implementing/content-delivery/caching.html#explicit-invalidation 

You can try it out .If you need more details i will suggest you to raise a ticket to adobe support team as well. Thanks 

Check the supported format in AEM DAM . Refer : https://experienceleague.adobe.com/docs/experience-manager-cloud-service/content/assets/file-format-support.html?lang=en#support-3d-formats 

Kindly referhttps://aem.redquark.org/2018/10/day-20-working-with-user-and-groups-in.html