After a few sessions, I think we got into the ballpark of what it should look like if we weren't Google or SmugMug: with a host of extra features (clutter detection, decent search, book and album writing, even calorie and activity tracking, and a few other conveniences)
The original intention was to build an application that would serve our family. But I feel like it's growing into something bigger as people are joining in. If you want to try, here's an invite code (capped at 50 signups): YRASHK-7ZXA-S3K3-DM8V