My feeling with this is that yes, no one is forcing you to pay for the game nor play it. Second point is, you are paying, if you are paying to the access to all of the additional features in the game, you don't need to yes, but that is what it is there for.
I will reiterate what has been said, find a bug free MMO. Your system is about the same as mine, except my video card is not as new, I have the occasional issue.
Crash to Desktop, simply start the game again.
Flashpoints crashing, never had an issue
Lag, well being in Australia and accessing a US server means at best I have 160ms ping. So I am used to it.
Small graphical issues, like head tails clipping, flaps clipping, streching graphics , I see them soldomly and if I do, I see them and continue playing.
Getting crushed in PvP, well that one, I will see if me getting better will help
There are bug, but other than a bug that prevents you even opening the game EVER I have not had an issue with it and enjoy the game. I am paying for not needing to buy cartel coins for unlocks. I buy them for funky things, but that is it.