This post is just me spurting my ideas about that I would like to see in this game as I think they could add more variety and diversity to characters thus making more people's characters unique to their choices.
1. Battle stances.
This would mostly be for melee weapons but in this game the way you fight is purely based around the weapons you use and your characters class but instead i feel the way we fight should have some form of choice such as a jedi guardian holding his lightsaber more loosely and making the strikes look quicker.
Other options would be holding the sword/lightsaber backwards behind the character like Starkiller does in TFU or also possibly having different ways a character shoots with their blaster etc.
2. Dark Side/Light Side and how it affects your character.
In this game the only thing different from dark or light is that if you go dark you get to look like you have some sort of incurable disease and some items being available to you depending on your dark/light level
I think they could add more to this such as speech choices only be available to you depending on how far dark or light you are and also they could add different effects to characters abilities to show their darkness/lightness in game. (It kinda sucks having light side jedi knight effects on a dark side jedi)
Side note: It could also affect how your companions begin to act if they have high affection with you, (from KOTOR 2 really) this is sort of done with Jaesa as she can be dark side or light side but not much more.
Since in the Star Wars universe Dark Side and Light side should be a bigger thing and so personally this should be implemented more into SWTOR in order to get that feeling your choices have a bigger impact on your character
3. Species Diversity
I know there are many posts about this already but for a game based around outer space and aliens you don't have many choices and I know SWTOR have started to do this so im quickly adding the species I've seen suggested and would like to see.
Wookies, Kel Dor's, Nautolan, Trandoshan, Bothan, Rodian, Selkath, "Yoda's species", Kaleeshians, Mon Calamar and also the Aqualish
I am aware some may have some story clash and gameplay problems and are very unlikely but it would be great for those who would just love to play as more alien like species.