What I feel would be great for the game in general is more diversity in how you build your class.
This would be following the basic principle of risk/reward choices, where choosing to specialise your class would result in shortcomings to other areas.
For example soldier class: let's say they have a bunch more options with levels of close combat, gunbash, faster recovery that kind of thing. For that specialisation they would sacrifice their ability to do well in longer range fights.
There are many concepts that already exist in classes that I think could be expanded to give more possible archetypes of each class, possibly a faster running sbd to sacrifice resistance/firepower/hp, expanding levels of close combat and dexterity to more classes, mandalorian speccing into either jetpack, heavy armour (SBD resistances), or a more gadget type build. More diversity within classes would be one of the best ways to move forward imo - instead of adding more classes just adding more routes for current ones to follow.