You will naturally HTFU as long as you keep a good posture. I like a lot of saddle to bar drop, and you ease up pressure on your hands and wrists by bending your back not at the hips, but at the spine, so that it is curved. Your core will develop so that it will support more of your upper weight, allowing you to remain in that position for longer without hand pain.
I'm suspecting your butt hurts because of your saddle. I use to experience a lof rear-end pain because my saddle was designed for a more upright posture. I switched to a flatter, narrower saddle and the pain went away.