Depends on which kind of pass you choose.  If you choose a 2 month global pass, Yes.  If you choose a flexi or select pass it will be good for the specific number of days of rail travel that you choose within a two month period.  In either case, you will have to pay extra for reservations if you choose to take trains that require reservations. 
No, UK and most of Eastern Europe aren’t covered.  From www.railpass.com: [=“arial, verdana, helvetica, sans serif”][=“2”]The Eurail network includes: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Hungary, Italy, Luxemburg, Netherlands, Norway, Portugal, Republic of Ireland, Romania, Spain, Sweden, and Switzerland.

[=”#000000”] [/][/][/][=”#000000”] No.  It does provide a discount on Eurostar, the chunnel train, but  you can often find fares cheaper than the discounted fare, particularly if you qualify for a youth fare.
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