WBC rules call for split shots out of a 14. I think you're looking for more complexity rather than sweetness from the espresso, since properly steamed milk will lend the drink all the sweetness you need.
Are you using a full extraction or a split shot?
Also, while you're tasting, keep in mind that the best extraction profile for a capp might not be the same thing as the best straight shot.
I tend to find a touch longer on shots for capps rather than for straight shots.
And as for steaming small quantities of milk, decisiveness is all. Find a steam wand/pitcher position where you basically don't have to move either while you're steaming. Another thing you can try is to steam slightly more milk, slightly thinner before you pull your shot and let the pitcher sit undisturbed as you pull your shot. Then pour some milk off (it will come from below your foam) and then carefully spin the foam and milk back together. That's how I like to do my macchiatos, but I've heard of people having success doing capps that way too.
And as for having a smaller steam wand, that may help. What machine are you on? You can swap La Marzocco & Synesso steam wand tips, and that has a huge effect on steam volume. Synesso makes both a high volume tip & a low volume tip, and the smaller tip is in my experience slightly shower than a La Marzocco. You might consider dedicating to smaller drinks by putting a slower tip on it.