I see your guide mostly as a point of view.
GS for me is now a big mistake to farm if you're going for rebels. Choose between him and lando, don't do both, at least not at the start.
QGJ is the past, Boba Fett will be new meta as he ignores taunts and absolutely destroys buffed enemies.
I don't recommend spending guild currency on characters, equipment is way too useful, unless you got any of the characters you mention on a data card and it will really help you stay competitive at ALL times.
STH is the best arena char, no argument there.
For galactic war I feel there are still choices. If you need more healing you can go Lumi, if you need single target damage you can go Biggs, otherway Phasma is the best choice. I'm not sure, but Greedo may have a future with the new Boba fett.
Chewbacca just seems like a huge waste of time for me, STH, Royal Guard and Sun Fac are just better.
Still, mine is just another point of view.
For my latest account I got the free Wedge and the team i'm pursuing is: Wedge (L), Lando, STH, Boba, Biggs. Currently ranking #2 on arena because the #1 spent over $300 and has all chars at 6-7 stars since day 2 of the server.