I've just beaten the game on Insanity with an engineer. I also had Kaiden and Liara in my team the whole time. Was definitely NOT easy.
However, I have not noticed the same problems that the OP is listing. First time I played this game, I played on Casual difficulty, and I rarely ever died. I would snipe, shotgun, assault rifle, pistol and I'd be fine. (I played a soldier though, maybe that had something to do with it.)
So my suggestion is this: Make sure you're actually playing on Casual difficulty, (at least for your first playthrough,) and pick the soldier class (again just for the first playthrough) and you should be fine. It'll help you to get used to the flow of the combat in the game, and should prove to be fairly easygoing and (hopefully) not frustrating.
If that doesn't work, then I don't know what to tell you, OP. This obviously isn't the game for you then, or you just need to practice a lot.
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And for those wondering why the planets are all desolate, it's because DVD's can only at most hold approximately 8 gigs of data, and Mass Effect barely fit onto the disc as it is. I believe that Bioware is aware of this complaint, as it's one of the biggest ones that people had with the game, and are finding a solution to this for ME2. I believe they will either sell 2 DVD's in the package, one for installing data, and one for play. Or they will offer fewer planets to visit, but much more content on each.
Also, if you read the codex it talks about how most of the planets in our solar system are uncharted and have little to no settlements on them. Which is really just a clever way for them to explain the fact that the planets have nothing on them.
