BOMB NOTE ASKS END TO U.S. INVESTIGATION
message, ostensibly from FALN and found by NYC police in subway telephone booth, calls for halt to Fed grand jury investigation; demands independence for PR and freedom for 5 nationalists serving Fed prison sentences; text of message detailed; recent motion in Fed ct to hold in contempt Raisa Nemikin for refusing to answer questions in connection with FALN noted; Maria Cueto, dir of Natl Comm on Hispanic Affairs of Prot Episcopal Ch, to appear before grand jury after spending day in custody until she agreed to be sworn before jury; illus of bomb damage at 2 bldgs (M)