That's pretty much it. Might also be nice for authors to check if their manifest contains invalid paths for example. pChat had the wrong folder name to LAM for years and nobody noticed.
As for textures, using the addon name as a prefix for the image path to allow them to be loaded relative to the manifest would be nice. Something like "AwesomeGuildStore:images/weapon/twohand_up.dds" should then load "AwesomeGuildStore/images/weapon/twohand_up.dds" regardless of the folder it is nested in.