It looks like your PC account will be as it is now and you will get a new copy of Horizons for the transferred account. Your PC account won't be affected. No merge option it seems.
No merge; it's a one-off transfer, leaving the original console account intact - so you can play both.
The reason behind the Cmdr name not coming over is that it may already be taken on PC (so it might work).
ARX is a legal thing - probably something to do with it being tied to real money - but who knows.
More stuff may transfer if they can work it out.
I'm not sure the reasoning around the Carrier; maybe due to naming or in-world persistence (since the original account doesn't go away)
I was personally expecting a big "it ain't happening", so this all sounded really positive.