I believe if you're going to do that humpty with a half roll the half roll must be on the upline. Other than that: you can push, pull, 1/4 rolls, w/e.

On the two half rolls in opposite directions: as long as you have a pause in center, you're ok. There's no criteria for the length of the pause, so technically it could be the length of the box if you want it to be.

On landing: most intermediate pilots go straight to landing because the sequence ends downwind. If you don't want to do that, you have the choice of flying a 180, doing a pass down the field, turn another 180, fly a pass down the field, and land.