Level 43 Newbie... What toons to build?

Hi all,

I just started playing last week and I am hooked on this game! I have been reading beginners guides to see what characters I should go after first but I think the guides are all outdated... For example, most say to get Sid from Arena store first but more recent posts say Sid is useless.

I bought the DS Pack, Droid Pack, Heroine Pack & Force Awakens Pack. I read that Mace sucks so I didn't buy the Jedi Pack. My best toons are:

43 Barriss 4* (leader)
43 Rey 4*
43 Kylo 4*
43 Chewy 4*

Talia 4* / HK 4* / Asajj 4* / Finn 4* / Wedge 4*
Poe 3* / Phasma 3*

I auto-battle LS/DS for gear and auto-battle Cantina 1A for GS shards. I can get to the last GW battle but can't beat it. I rank around #200 in Arena. I only spend crystals on 50 and 100 refreshes.

Any advice on who to go after in the stores? I have not spent any store credits yet. I only buy gear shipments with credits.

Any help would be appreciated. Thanks!