Eh, probably every first-time ME players suffers that. Hell, IIRC my Shepard got killed in one shot by the Armature while my squadmates are still standing; first time I realized that Shep can't die at all cost.
Then there's that time when the Tresher Maw impaled my Mako and killed everybody.
Playing ME1 is like riding a bicycle - the first few tries will bruise you.
Tali is actually quite useful, moreso in 1 than 2 at least since she can use Carnage and Overload.
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Since I won't be getting Fall of the Samurai until June at the earliest, I'm currently replaying Empire Total War. It's still fun, but Shogun 2's interface is more user-friendly.