all I really need to do is to make sure that I increase my stitches til the sweater is large enough for my chest.
Yep, isn't that wonderful! When you get to what you think the chest size should be, do try it on, put some of the sts on another needle or scrap yarn. That way you can decide if it's too long to the underarm, too short, too small, too large, and adjust by taking out a few rows or adding more.
If the neck is large, it won't 'block' smaller, that usually stretches or relaxes the sts. You could pick up sts around the neckline and knit a few rows in ribbing to make it smaller though.