Yeah, my guess would be grass rendering as well. I really notice it on worlds that have grass - Alderaan and Belsavis. I can usually tell when I'm going to crash as well because I use a second computer to monitor processes on my gaming rig and I can see the second swtor.exe process start to sky rocket in memory usage as soon as I get on a world with grass. Hoth and Nar Shadaa....no issues. Normally the second swtor.exe process sits between 500MB and 700MB of RAM. Use your mount or speeder on a grass world and that guy sky rockets to over 1GB of RAM usage in under a minute. At that point, a crash is imminent.
The nice thing is that sometimes it doesn't BSOD and the game just freezes. So I can use the second computer to kill swtor.exe and then I'm fine and just restart the game. But I will try lower the grass rendering. I know I did lower it a bit on an earlier troubleshooting pass and it seemed to help - not as frequent crashes. But I had also turned off my paging file in Windows 10 as well ( some other thread somewhere mentioned it). It has gotten better but now I'll turn grass rendering distance to 0. What I've been doing is when I notice the second swtor.exe process is over 1GB, I jump to my stronghold and back to planet which resets it back to about 600MB or RAM usage....it buys time and lets me slowly get around whatever planet I"m on.
Let's hope they fix this soon. I was unable to go back to the 348 driver - can't enable Surround SLI - wants to kill windows processes in order to enable SLI surround and those processes just restart as soon as I kill them. Managed it once and it just buggered everything up. So now I'm running the latest driver.