Are there any development tools th...

Do I have to use EJB 3 to use Seam?

Seam provides a number of JSF components to support the use of Seam with JSF such as integration between JPA and drop down lists and conversation control.

Seam doesn't provide any general / visual components (such as a date picker) as there are many great component packs which include components like these. We suggest you look at RichFaces or IceFaces.

But Seam used to provide a date picker - why was it deprecated?

We deprecated the date picker because it was taking a lot of time to maintain, time which was better spent on developing the core of Seam. There was no way the Seam date picker could be better than that in dedicated JSF component sets.