I have had similar issues with my TSL install... and when I had the old 4-disc K1 install and not the BoPC version. The soft shadows were not, I believe, an issue though.
I wonder, does the game start in windowed mode by default for you?
You could use your GPU control panel to set the AA for you.
Want to play a game of ME3MP?
Qui-Gon_Glenn on the software of which we shall not name.... add me and the enemy shall fall in chunks of crimson salsa