As much as I love this series I can't do a renegade playthrough killing off squad mates.It's one of those things where you do it once, realize how awful it is, then every other time you do a "renegade" playthrough you just pick the dickish options while still keeping as many people alive as you can since it's just more fun that way.
I'd just kill week in ME1 and not put him through a worse fate in ME3.