How dod Queen heal that quick and i think Marco flames stop healing him has fast the more he fights. Which is why after Marineford he had bandages on. Queen been with Chopper on the floor for like 10 chapters. So King is the only person he had to worry about and King isn't defeated
Unlike Marco who had to share his attention on 2 opponents(King and Queen), Queen had more room to spare.
The time Marco takes to go and beat King, gives Queen more room to recover / do something else. The time Marco goes back to Queen and kick him, it gives to King more room to recover / do something else.
If neither was there, all the focus Marco had to share would be entirely focused on one opponent and thus the opponent would be speedblitzed more, would be damaged more, etc, etc while Marco on the other hand would be less damaged, would be less pressured, with much more room to spare
As for the current King vs Marco battle ? Well as stated
- Current Marco is weakened from his battle against both King and Queen(also having to share his blue fire to protect the samurais)
- Perospero might be doing something with his arrows
- Current King's condition is unknown