1- There's still a lot of benifit for subbing if you want to do stuff like operation, having multiple character, not paying for every new content etc.
2- I know a lot of people who would not play league of legend if it wasnt free. I also know people spending money for skins.
I think a lot of people will try this game because it is free and some of them will sub, some will buy stuff at the cartel shop and some will be a waste of space. But really who cares, as long as they get more money from this game to produce more content i'm fine with it. And as a bonus i get free cartel coin to spend at the shop with my subs, i always thought swtor lacked fluff.