who should i focus on to upgrade?

LifeandDeath

should i just get the last star for paploo chirpa and scout or get someone else higher instead? any advice is welcome

Hortus

The optimal Ewok squad is Chirpa-Paploo-Logray-Wicket-Kneesaa.

Chirpa and Paploo is a must, scout is mostly useless but could help as damage dealer until you open Wicket. Kneesaa is extremely powerful and the real game changer for ewok squad, but if your main goal is open C3P0 as soon as possible then Chirpa-Paploo-Elder-Logray-Scout is probably the fastest way.