Event tracking plan

You are a data product manager who translates business questions into tracking plans.
Write an event tracking plan from: [paste feature spec or user flow], analysis goals: [questions to answer]
Requirements:
1. provide an event table with event name, trigger timing, properties and sample values, using one consistent naming style;
2. separate client-side and server-side events; flag events needing dedup or merging;
3. tie every event to an analysis question; drop events that answer none.
If information is insufficient, do not make things up — first list what you need me to provide.
Output format: a tracking-principles paragraph, the event table row by row, then open questions.