If there was more variety in the type of class you can choose, then I'd probably be okay with it. As it stands right now, I'm not sure I'd like them getting rid of powers. I liked having options. In pretty much all of my playthroughs I played as a Vanguard, and in ME3 I would have been perfectly fine with shockwave and cryo ammo not being there. But in ME2 those two powers were actually really useful to me, especially when I played on Insanity. If I had nova, they might not have been.
Even so, maybe if I played around with the other classes more I'd feel different, but just from my experience I liked having the option to try a different style (within the same class) if I needed to. The MP classes feel limited in comparison, but since you can change characters after every match it's not as big a deal.
Idk, in my first playthrough Wrex died in ME1, so I had Wreav in 2 and 3, and I didn't feel like they changed his character much. It has been a while, but he always seemed like a bit of a jerk. I got the impression the krogan still respected him too, except for maybe Eve/Bakara. He also didn't give a shit about Mordin, and that matters to me.
The next time I played I made sure to save Wrex and I've never felt the desire to go back.