I'm having the same issue.
I don't really keep track of fps, and I'm not even really sure how to do so, but I have the same lag issues.
Anytime I arrive in an area, new or old, which causes the name of the area to come up on screen, anytime I open the map, and anytime I have a quest updated, there is about 1-3 seconds of lag. I haven't had any crashes *crosses fingers* thankfully, but it is a pretty big annoyance to freeze everywhere, especially when you're fighting and a quest updates.
I came to Taris from Coruscant, so I haven't been to any other worlds, and don't know if they are having the same issue. Hopefully the team can find out what's causing it and possibly get it fixed, especially before launch.