How can I store sources, effective dates, and confidence for every property in a knowledge graph?

What I am wanting to do is ensure that every property in a knowledge base comes from at least one source. I would like to ensure that every edge is spawned (or at least explained) by some event, like a claim or measurement or birth. I'd like to rate on a scale the confidence that some property is correct, which could also be inherited from the source's confidence rating. Finally, I want to ensure that effective date(s) are known or able to be calculated for every edge and vertex. Is this spiraling into an impossibly large goal? I am not sure where to draw the line, but I do know that I need to be able to provide a source for all information.

My use case may help. The goal is to create a knowledge graph on drug use and experiences, populated with both user-generated data as well as info sourced from public data sets, such that every Dose links to: the affected User, the Drug ingested, the route of administration (ROA), and the amount taken. Users can also log experiences and effects as they notice them, so I would like to suggest common Effects for the Drug taken recently (still active), and I'd like to project the duration of action based on historical Doses (from the User, other users, and medical literature). Since this is medical data, I want everything to be in order, but I am not sure that this level of granularity is possible or desired. It is to me!

The reason for the temporal aspect (keeping track of times) is to show on a timeline what drugs were active and when, then as you scrub the timeline you can see effects pop up and mutations to overall condition as reported by the user or documented in source literature. Let me know if this does not make any sense and I will try to explain it better (or learn that it makes no sense).