for the toc, for now, you'd better create it manually...
and if this is not practical for your book, it's a sign that you'll probably have other problems in using scribus further on...
for the index it's a different issue...
concerning the index: scribus does not support indexes, either.
there are a few workarounds... if you still are interested in using scribus for your project, i think that we can discuss about it...
and, for the future, there are solutions in the working for both the TOC and the index!