How high should I take my Phoenix squad?(EP/Thrawn)

Take your pheonix to g8 lvl 85 with all skills except zetas. But you can and should take ezra to g10+. This will get you thrawn 7*. On top of this, ezra is a great attacker to add to jedi or rebel squads in guild events and raids. If you decide to use ghost and phanton in fleets then by all means take them further, but for arena/pvp use g8 is plenty. Feel free to take Ezra higher as said earlier, as he is really useful in events that need large rosters. P.S. he works great with OG leia. Double and triple tap nightmare. Kanan is also beconing a viable second string tank for these type of events. He sits behind GK and old ben on LS but about on a par with STHan