First, I can't help but suggest that you might find better travel advice in Wikitravel than in Wikipedia

Second, you've got a long list of attractions for Delhi, but I find it more of an "experience" than "attraction" kinda place, so be sure to leave some time for a nice wander or two in the Old City (Chandni Chowk). One attraction missing from your list and very much worth a visit is Akshardham, a gigantic temple just across the river and completed only in 2005 -- imagine being in a red sandstone Angkor Wat before it fell apart into ruins, and you'll have some idea of what to expect.

And third, it's going to be a pretty long daytrip to go to Jaipur and back. Many people favor the trains for Jaipur and Agra, they're faster, more predictable and rather less nerve-wracking than long drives on Indian roads, even if you're in the passenger seat.