Actors will have type / movie / actor and look like this in a dump:
ns:m.010q36 rdf:type ns:film.actor.
You can find them all in a few minutes from a compressed dump with a simple grep:
zgrep $'rdf:type\tns:film.actor.' freebase-rdf-<date of dump>.gz | cut -f 1 | cut -d ':' -f 2 > actor-mids.txt
This will create a MID list in the form m.010q36 , which represents MID /m/010q36 .
Using the MID list, find all the rows that have that MID in the first column, one of your desired properties in the second. You can do this with Python, grep, or the tool / language of your choice. Of course, if you use a programming language such as Python, you can do an initial search.
Wikipedia and IMDB names are stored as what Freebase calls keys and looks like this (MusicBrainz and Netflix are included too):
ns:m.010q36 ns:type.object.key "/wikipedia/en/Mr$002ERodgers". ns:m.010q36 ns:type.object.key "/authority/imdb/name/nm0736872". ns:m.010q36 ns:type.object.key "/authority/musicbrainz/87467525-3724-412d-ad3e-595ecb6a3bfd". ns:m.010q36 ns:type.object.key "/authority/netflix/role/30006685".
Keys can be encoded (for example, on Wikipedia). You can find documentation on the Freebase wiki on how to deal with them.