MSIX has the ability to add a description via MSIX Packaging Tool and when you create the MSIX App in MEMCM, that information is added to the field automatically. Would like to request to provide ...
Jason,
For #1 its a great ask for the MEMCM Team. There could be a declared path that is read from the MSIX file. Nothing technically needed to be added to MSIX.
For #2 you can use the command line to create an MSIX: Create a package using the command line interface - MSIX | Microsoft Docs
Configuration Manager has PowerShell interfaces to create an app and manage distribution points: Configuration Manager PowerShell cmdlets - Configuration Manager | Microsoft Docs