For the former ffmpeg command, you'll need to start the stream in stream manager to ingest it. For the latter (flv/rtmp attempt), you should just be able to play it back. I don't see the publish event in your logs
INFO stream publish myStream
Try the following command and see if it makes a difference:
That is the recommended way to use FFmpeg, as an mpeg-ts encoder, then using .stream files and the StreamManager or /conf/StartUpStreams.xml to start pulling the stream.
Matt's example works as well, and is using FFmpeg as an RTMP live encoder, so you don't have to use StreamManager or .stream files to start the stream. It should be available for playback as soon as published. Make sure FFmpeg can reach Wowza. You should see a publish event in Wowza as soon as you start the stream with the RTMP publishing method.