I've found conflicting information regarding the validity of Eurail in Paris. Eurail.com's list of airport-station links lists the connections between Paris and the CDG (Roissy) and Orly airport, both operated by SNCF, as not covered. However, Eurail.com's list of participating companies mentions “SNCF” without restrictions. Some other sources, e.g. Rail Europe and EurailTickets.com, claim that those specific connections are covered, which suggests that Paris suburban trains operated by SNCF are covered. Participants on this forum thread give conflicting information and suggest that the rules may have changed at some point.
In any case, the RER line to Disneyland is operated by RATP, not by SNCF, and no RATP line is covered by Eurail. Of the main suburban tourist destinations, SNCF operates RER C including the branch to the Versailles palace, and the part of RER B between Roissy airport and Gare du Nord. RER A to Disneyland and the metro in Paris are not operated by SNCF.
In any case, using an Eurail pass for local transport would only make sense if you also make a long-distance trip the same day, otherwise it would make local transportation extremely expensive. For Paris, the general advice is to buy either a day ticket (Mobilis) if you travel a lot, or a booklet of 10 tickets for local transport. Most tourist attractions are within the city limits, where an ordinary ticket-t suffices. Disneyland and Versailles are outside the city limits, in zone 4 and 5 respectively. Note that most tourist information in English mentions the Paris Visite pass, but that's mostly a tourist trap; the Mobilis pass or individual tickets usually comes out significantly cheaper cheaper (e.g. €15.20 for a return between the city center and Disneyland, €17.30 for a day pass that covers this trip, €24.50 for a 1-day Paris Visite pass that covers this trip).
For Zurich, Eurail states that the pass is valid on the train link from the airport to the city, and several secondary sources claim that it's valid on all S-Bahn trains. Generally, in Germany and Switzerland, it seems that all S-Bahn trains are covered by the Eurail pass.