Not sure because I see its mentioned in 6.3 documentation that Once user sync is enabled, only newly created users and groups are syncrhonized.

Yes its the same. Infact its compaction is one of the phases of maintaining the repository.The mechanism will reclaim disk space by removing obsolete data from the repository, and has three phases: estimation, compaction, cleanup. In the past the revision cleanup was often referenced as compaction.R...

You may try using event listenershttps://helpx.adobe.com/experience-manager/using/events.html

You can always use dependency finder in AEM to check for the exact dependencyhttp://localhost:4502/system/console/depfinder Did you try adding this:<dependency> <groupId>com.adobe.cq.sightly</groupId> <artifactId>cq-wcm-sightly-extension</artifactId> <version>1.3.8</version> <scope>provided</scope> ...

See this article and try something similar http://scottsdigitalcommunity.blogspot.ca/2017/09/using-wcmusepojo-class-to-populate.html

Asset asset = resource.adaptTo(Asset.class);String fileName = asset.getMetadataValue("dc:title");if (fileName instanceof Object[]) {Object[] titleArray = (Object[]) asset.getMetadata("dc:title");fileName = (titleArray.length > 0) ? titleArray[0].toString() : "";} else {fileName = asset.getName();}Pr...

Can you elaborate the problem and share STR ?

Refer to https://helpx.adobe.com/experience-manager/using/graniteAPI.html and https://helpx.adobe.com/experience-manager/6-3/sites/developing/using/reference-materials/diff-previous/changes/com.day.cq.dam.api.AssetManager.htmlor do something like thishttps://raw.githubusercontent.com/Adobe-Consultin...

refer to https://helpx.adobe.com/experience-manager/6-3/sites/developing/using/access-jcr.html

try creating package with setting the AC handling value to Overwrite