yes you can buy off negative traits if you choose to.
the big difference between life modules and point buy, is that via life modules you can endup with more than the 10% of negative traits if you want.
I will also say that it mentions in the architypes section that you can also tweek some of the traits if you don't like the default ones by substituting an equivalent point trait.
so lets say for the sake of argument that you replace paranoid with an equivalent point cost enemy, or addiction because you feel like its a better fit for your character concept. note this would have to have the gm approve it, but it should be fairly easy as long as the value is the same.