Jodhpur street food is generally spicy. You should definitely try the Mirchi Bada, Ma Mawa Kachori and Pyaaz Kachori, with the famous Makhaniya Lassi on the side.
Just came from there over the weekend. Mehrangarh fort takes time - easily 3 hours if you really want to spend go through the collection in details, and appreciate it completely. Ummaid Bhawan Palace (Read More) takes another 2-3 hours, and I would recommend to visit them both on different days. The rest of the attractions should not take so long. So I would say, please take upto 3 days if you want to really dig deep into all the different attractions of Jodhpur, although 2 days could be sufficient as well.