That GM wouldn't do anything to them for telling them all that information, just like they wouldn't do anything if you told them you bought gil. People don't get banned for windower. :\
now tell the GM your FPS is 23.6 (by just looking at your screen), that your 35,268 tnl and 5,529 tnm (calculating it in your head in a split of a second), your party's tp and mages mp outside your party (by paying great attention to how many hits they land and by guessing of course) and finally the distance to your selected target (judging by your sharp eyes of course) and then tell me if that GM is still "people".