Thanks, and I appreciate the questions:
1. Glue4 is not a query storage nor technically a "real-time" database, so the trade offs are different (you don't have to use a proprietary SDK to query your data, everything is in your Redux store as a JSON object). As well, this is a plug and play Redux add-on, you don't need to change anything about your current application.
2. It's represented as JSON-serializable data. The storage abstraction is an implementation detail. Currently it's literally serialised to disk, but we can just as well store it in DynamoDB, Mongo, PostgreSQL's JSONB column, etc. We will eventually support complex data (like images, videos, BigInt, etc) and transparently serialise/deserialise them for you and persist them for you in the appropriate storage (i.e. if you add an image to your Redux state as a user avatar, we will upload it to a blob storage and send it through a CDN for future fetches, all transparent to you as the developer).
2.a.: Yes, for the current version that is the case. Local persistence (offline first) is definitely something we want to support down the road!
3. A high level roadmap is actually available on our website if you scroll down :).
Let me know if there's anything else :D!
