How can I get a list of all the events fields including their data type?
Look at fieldsummary command. This should give good summary of the fields available in the event.
http://docs.splunk.com/Documentation/Splunk/6.2.0/SearchReference/Fieldsummary
Adding an eval like this can give it type as well.
your base search | fieldsummary | eval isnumeric=if(isnotnull(min),"Yes","No")