This faq covers operation of the family amateur radio digital modes available in KIJT Joe TTaylor's software WSJT-X as well as obtaining, compiling and installing the software itself
Under most circumstances no. The waterfall represents the signal being presented by your radio to your computer soundcard or outboard audio interface, not the signal as seen by your radio.
This means the station seeks contacts with distance stations only. Note the meaning of "DX" can vary according to context (mode, band, etc).
The caller is looking for contacts with specific US states. In the example, Alaska, Hawaii and Vermont.
This is shorthand notation for "roger-roger 73". It is a shortcut in standard QSO exchange of RRR,73,73. Note: this practice is disfavored by many as RR73 is a maidenhead grid locator square (albeit an uninhabited stretch of Arctic Ocean)
No, these are bad decodes where the decoder software does not have enough information to produce correct results.
Mostly likely culprit is time syncronization. JT modes require strict time synchronization to a well-known time standard. (See question below)
Windows: The time synchronization built into the Windows operating system is usually not reliable or accurate enough for use in the JT modes. Use a third-party time synchronization program such as Meinberg NTP or Dimension 4.
Linux: Most Linux distributions have NTP enabled by default. You can verify its properation by running "ntpq -c peers"
All OS: using servers from the public NTP server pool is recommended. See this link for more info.
First, enable "double click on call sets TX enable " in the WSJT-X preferences. Second, enable the automatation features of "Auto Seq" in the main window.