I'm forming a company with [NUMBER] co-founders. Help me think through the key terms for our shareholder agreement: 1) Equity split rationale (provide framework), 2) Vesting schedules and cliff periods, 3) Drag-along and tag-along rights, 4) Right of first refusal on share transfers, 5) Decision-making thresholds (simple majority vs. supermajority), 6) Founder departure scenarios, 7) IP assignment provisions. Identify the top 3 clauses founders most commonly fight over and how to pre-empt those conflicts.