The full extent of care I lavished on my hibiscus (tree form, single trunk, approx 5'-6' tall, potted, zone 8b-9a):
water; every couple days
sun; 4 hrs per day (on covered balcony)
hose aphids off leaves; every other day when needed (stopped when ladybug nymphs showed up, after frantically googling to discover what sort of horrible new bug THIS was)
whack off crazy branches; when it got unsightly
I never fed it, that I recall... tho it may have received some fish emulsion or seaweed when all the container veg got fed. I never pruned it according to any proper seasonal schedule. I think my cats used it as a scratching post (and occasionally litterbox). That sucker bloomed constantly as long as it was above 75* and the aphids were relatively under control.
I did plant nasturtiums in the pot with it one year... another year was marigolds and yarrow, or cat grass (oats, wheatgrass), catnip...