Yeah, not being able to disable mines or open containers which require Security won't kill you :D
I always take the Handmaiden and Mira.
And about the Kreia thing, sometimes you just have to take the DS point in order to gain influence with your characters. There're tonnes of LS points everywhere. (That is, if you're playing LS, of course. You'll have no problem if you're DS.)
Just a question, do you get more influence with Atton if you're LS or DS? Because every time I play LS I can turn him into a Jedi, but the one time that I tried DS he wouldn't tell me about the female Jedi...