There are good points there except about knockback. I don't remember if enemies take damage from being knocked into walls. However rocket dash does do pretty decent damage when an enemy is knocked into another enemy.
I don't know about 'into another enemy', because I've never seen enemies line up like that, but slamming into them yourself does 2-3 damage, which is worthless, and bouncing them off walls doesn't do anything.
Rocket-dashing into someone
should do at least five damage, so it's at least noticeable, and hurling them into a solid wall should do ten or so.
That way you could rocket-dash people into walls to kill them, or bounce someone off a wall with the grav-knuckles for bonus damage.
Instead you're just throwing people out of your own attack-range.
I immediately switched to the Shortwhip, because it's overall just far superior.
You can't attack twice in one turn with it, but you couldn't really do that with the knuckles either, and it does about ten more points of damage, which isn't resisted by armour.