Pickup height is almost entirely subjective, but you'll also find most pickups have a sweet spot where they've got oomph without being squished, and open without being quiet. You might prefer some pickups really backed away to open them up, whereas others you might prefer closer to the strings for more "oomph". It's very easy to overthink, but thankfully even easier to just pick up a screwdriver and try it out!
From where your pickups are now, raise them a few screwdriver turns and listen to the difference. Then put them back to where they were, listen to the difference. Lower them a few turns; listen to the difference. Once you've got an idea of the extremes, get them roughly to where you liked them best. Then try raising/lowering a turn or two at a time until you find your personal sweet spot.
