Been trying FT8 for a while now and posted questions on the 'digitalradio' forum but got no responses, so will try here:  

1) Running FT-8, when I double-click on a station calling CQ, WSJT-X frequently starts transmitting immediately instead of waiting for the next transmit window.  Is this normal?  Is it because there's still enough time left for a possible decode on the receiving side?  I also notice it often takes multiple answers to a CQ to get a response.

2) How much power are folks running.  I sometimes see a very large difference between sent/received signals, especially from stations working Europe.  A post on the Flex forum said some are running 100's of watts, up to the full 1500W at times!  

3) In the Message section, what is the ~U.S.A. and !Italy etc?  Are these DXCC entities and is there any documentation on the use of "~" and "!"?  I scanned the most User Guide including FT8 and didn't see it. 

Thanks,
Dick
KF5SA