I somehow missed your original mail about jbuilder 1.0~beta18. Is there
already someone from the team looking at your updated package? Otherwise
I can look at it over the weekend.
Concerning your question about a package rename : that depends on whether
it is a rename of the source package or of a binary package. Renaming a
source package is not possible, so you would have to upload a new source
package and ask for removal of the old one. Renaming binary packages is
easier : you just change the name in the debian/control file, and you
add Breaks/Replaces between the old binary package and the new one.
However, this counts as a new binary component, so it has to go through
the NEW process.