The autoscroll can be skipped by bouncing on the bats until you reach near the top of the screen, and then flutter to the right over the first bit of terrain.

The bats can be despawned shortly after for a bit by jumping to the left over the lava to the left of the star cloud, after falling and landing after the autoscroll skip.

Beware despawning red coins near the bullet bill launcher!

For the end section, the strat used in the video is much more difficult than simply firing an egg at them from a safe distance, and then riding poochy to the exit.