Quote - If you would like to offer positive ideas for what a cool DL and install system could be like, then please do.

This sentence embodies the core problem, you're thinking about having something new and "cool", rather than putting a lessor amount of effort into making improvments to the current setup that have been requested for a long time e.g. :-

1. Improve the current installers so that they can be run in batch mode.
2. Improve the download reset architecture so that multiple items can be reset at a time (e.g. by order, by all items updated since last download, everything etc.)
3. Improve (i.e. make reliable) update notification (as emailing is patchy, consider using some on-site mechanism which is an automatic part of the update release process rather than a manual step).