I also don't think having a javascript function that inserts the Launch code is a supported implementation. More info on how to deploy Launch can be found here

Here is the details for all new node properties to these similar nodeIn order to make it safer and easier for customers to understand what areas of /libs are safe to use and overlay the content in /libs has been classified with the following mixins:Public (granite:PublicArea) - Defines a node as public so that it can overlaid, inherited (sling:resourceSuperType) or used directly (sling:resourceType). Nodes beneath /libs marked as Public will be safe to upgrade with the addition of a Compatibilit...

You can keep that jar in local/central repository and embed it in maven-bundle-plugin in pom.xml of your project's bundle. It will be available with your project bundle. You might get import errors of few the packages which might not be needed in run time. You can neglect those packages as well. Refer this article for details.

You can refer following doc for supported formats Assets Supported Formats AFAIK , WebP is not supported OOTB.

I have answered a similar question on StackOverflow: https://stackoverflow.com/a/46822901/5633515You should be able to use my answer with very minimal changes to display the values you want.