(2.1) Where should I ask which movies actor starred in?

You shouldn't.  Check The Internet Movie Database which can be accessed
via a World Wide Web "browser" :

  < http://uk.imdb.com/ >                   (European users preferred)
  < http://us.imdb.com/ >                   (USA/rest of world preferred)
  < http://it.imdb.com/ >                   (Italian users preferred)

or via email to <mail-server@imdb.com> with subject "HELP"

The "Movie Database: Frequently Asked Questions List" is posted to the
movie newsgroups regularly. Copies of the Movie Database FAQ may be
obtained by anonymous ftp to rtfm.mit.edu under
< ftp://rtfm.mit.edu/pub/usenet/news.answers/movies/movie-database-faq >,
or by sending e-mail to <mail-server@imdb.com> with the subject "HELP FAQ"

If you are interested in adult video performers, there is a web based
searchable database at:
< http://home.eznet.net/~rwilhelm/asm/dbsearch.html >
This database is maitained by Peter van Aarle, one of our moderators of
rec.arts.movies.erotica.  The group of moderators maintains an
informative general interest site/archive at site
< http://www.rame.net/ >.
The Adult Film Archive maintained by the Bio Keeper can be viewed at
< http://www.hypervil.com/biokeeper/public/ >.