Some questions about sewing with an interlock knit

I have a lovely piece of gold-colored interlock knit that I'd like to use to make the School Photo dress. I'm wondering what kind of lining material I should use. The interlock has a very moderate stretch in both directions and is of a medium weight. Not sure what it's made of, but possibly all cotton or cotton/poly. I'm also wondering if I should grade bulky seams with this fabric. By that, I mean trim the margins after sewing a seam to slightly different widths to avoid a bump appearing on the right side of the fabric. Instructions generally say to trim to 1/4" no matter how many fabric layers are seamed together. Thanks.