1: If you are asking whether it's possible to submit a request for reference data with a filter applied ("Place of Listing" = "Y"). Then, this is not possible with our request API (SubmitRequest & SubmitFTPRequest). You will need to apply the filter on their end.
2: This would depend on the operation. In the SearchRICs operation, fields can be defined without specifying the message type. In contrast the SubmitRequest operation requires that the messageType be defined for each set of fields. Each messageType will have their specific fields. Refer to <GetMessageTypes> for a full field list. MessageType and fieldList elements are all containers.
Under the "Reference Data" field tree, there are categories for "Equities" and "Warrants". In the API methods for SubmitRequest and SubmitFTPRequest, these are specified in the "MessageTypeList" parameter. Multiple messages types may be included in a single request. Under each MessageType, a list of fields can be specified that are specific to that message type.