We are booked for a morning tour at Keukenhof. Is it feasible to see Delft the same day, or is that too ambitious?
Are you staying in Amsterdam the night before and after?
Yes, you can take the Keukenof shuttle bus to Leiden when you leave. From Leiden catch the train to Delft.
I would give each area their own day, if possible. Just seems like you'd be playing "beat the clock" all day to stay on schedule, rushing through. And you need lunch. I loved Keukenhof, and just sitting on a bench and enjoying the spectacular gardens is a memory I'll always have.
Enjoy your trip!