There is also a weekly that requires the completion of 10 GSI dallies and requires purple reputation item and 20 basic comms on completion. Geek Out.

Kevin Kao. Tuesday 7 am EST. You can reach the cap if you do GSI dallies on 7 planets and then top it off with a purple rep.

Speaking with characters offers choices in your interaction, and the choices you make will determine that character's feelings towards you. Well now we know it is 15k for champion then the previous assumption is incorrect. Thus right now we have no idea what Legend is.