The separatists => Padmé + GR route is a good alternative to the oldschool Phoenix => Thrawn + EP => R2D2 => CLS route. Your Padmé team will probably remain viable in squad arena for a long time. Nute is great in Padmé's event.
You will collect some good pilots along the way either way. You could try going all-in on farming pilots to try to hit high ranks in fleet arena for those extra crystals. Also you should plan for beating the zeta material challenge. (As far as I remember it requires 5 DS ships at 4* or better and 8 ships total at 5* or better - not 100% sure, though).
Regarding hard node battles:
The best investment of your crystals would be to buy the 3x 50 crystals normal energy refreshes to farm more hard nodes. At your stage you still need to farm a lot of characters. It's not at all wasted. Also, if you get som powerful allies (f.ex. the strongest players in your guild, or advertise for some on these forums) it will help your greatly to progress in LS/DS battles.