Covi, where in your hips do you feel sore, and do you routinely do any other physical therapy or strengthening exercises for your hips? I am trying to determine whether the soreness is due to weak muscles in the area. I assume the pain is in the front of the hips (hip flexors)? If so, I know that for cycling the two muscles from that region that usually need strengthening are the psoas and iliacus, which the core exercises above help with.
You could sub them as follows:
Sub for Reverse crunch- instead, lay down on your back with both legs/feet up towards the ceiling. Lower one leg at a time as low as you can go without getting your low back off the floor, switch sides (10 each leg). If this one still hurts, I can give you an isometric hold (wall squat with pelvic tucks).
Sub for Boat row - instead, do supine knee drops. Lay down on your back, feet off the ground and knees bent forming 90 degree angles. arms out to a “T”.Keep upper body relaxed and drop your knees to one side as fas as possible without letting your opposite arm and and shoulder blade come off the floor. Alternate sides (10 on each side; 20 total).
Let me know how it goes.