You passed your CFI, you'll do fine on the interview. The only thing to watch out for is you psyching yourself out.

I did my initial HP/complex in a Comanche. They are an absolute dream to fly. They're not any more complicated than an Arrow or 172RG, they're just faster and heavier. Don't be scared of them!

You're a commercial pilot and certified flight instructor, it's an airplane. Make it do what you want it to do. You've already proven that you're capable of doing that.