Everyone who uses iTunes U is responsible to understand copyright regulations and how it applies to uploaded content. You are encouraged to review the UB policy on copyright and the UB Libraries Copyright Information Resources page. iTunes U content is stored on a server at Apple. Therefore, you should also review Apple's iTunes U Copyright Overview (PDF) and Apple's Copyright Claim Policy.
No. There is no Digital Rights Management (DRM), which is electronic protection that limits usage of digital media, in place for content placed on iTunes U.
No.