EGKK
You didn't write clearly what you explained now. However I am the one who started this thread five years back to get an answer and all these thoughts went through my mind. So later I asked the airbus about it also stating that unnecessarily moving the flap lever to 3 causes the VFE to be displayed incorrectly. They did not give the reason of safer GA in three. I will reproduce a small part of it below.
I agree with you that selection CONF 2 during approach, and maintaining CONF 2 for Go-Around could have been less misleading for the pilot. But the rationale of selecting CONF 3 for A320 family aircraft is historical, as this configuration has been proved, in terms of certification, as being the optimum one in terms of handling qualities in alternate law.
Perhaps Airbus themselves had noticed it because in A330 they had changed it. If you see the same failure in A330 QRH it tells you to land in flap2.
Also flap retraction of one step in all cases is not required and this was discussed sometime back. You can search for it. Retraction of one step in GA is due to high drag in flaps full. Conf1, 2, and three are take off configs and do not mandatorily require retraction especially in 1 and 2. There is also airbus discussion on this.