Can I do the Amalfi Coast and Tuscany in one trip?

Yes, if you have at least twelve days — they're about five hours apart by train plus transfers, and both deserve real time. The sane version is Rome in the middle: fly into Naples or Rome, do the Amalfi Coast first while you're freshest for the driving and the stairs, then train north to Rome, then Tuscany, and fly home from Florence or Pisa. In ten days it becomes a transfer-heavy blur. The other honest option is to swap Amalfi for a coastal stretch closer to Tuscany — Cinque Terre or the Maremma — and keep the whole trip inside a two-hour radius.