I did two separate playthroughs.

First one, I made all the decisions that I wanted to make, and I was happy with what I chose. Except I was a soldier, which seemed pretty wack compared to my second playthrough when I was throwing bitches off of cliffs. Way more satisfying.
2nd playthrough my Shepherd wilded out. Slapping bitches, trying to fuck anything with a pulse, letting species go extinct, and I didn't explore the universe nearly as much. But I loved the biotic powers.

I doubt I'm going to have time to do another playthrough this month.

So, is there any way I can choose my first Shepherd but change his class from soldier to something different to the 2nd game without affecting my prior choices?

Or am I just going to have to roll with genocidal Shepherd that pistol whips anyone that looks at him sideways?

Go Tigers