[CecilOne]

It all comes down to judging what the runner was doing when rounding 1st. Was she just rounding or rounding on her way to 2nd? If she was on her way to 2nd, she apparently would have made it without OBS. If she was not on her way to 2nd and only went to 2nd because of the OBS, then I would say she would not have reached 2nd and should be placed on 1st.
The trot, semi-walk only serves to encourage the throw from F6; because if she was running, 2nd seems easily reachable. She would then be standing on 2nd or past it, probably no throw, probably no OBS effect, etc. Is the trot, semi-walk legit baserunning? Yes it is. Is it taunting? Probably not.

As to the OBS vs. CTR rule, the application of not being put out between the bases where the OBS occurs would seem to apply to the attempts by the defense to put out the runner. In the example,
"BR ... snip ... rounds 1B, collides with F3, ... snip ... The ball goes back to F1 in the circle. BR, stationary, then retreats toward 1B and reverses direction or stops again"; I would say the CTR supersedes because the defense has stopped trying for a put out. The ball was in F1's possession before retreat to 1st, let alone the change of direction; so a clear example of the CTR intent.