I am looking for something like this whereby I can add multiple lines above the player's name.
No, armor stands do NOT work because teleporting them directly to the entity have a slight delay, unless there is someway to resolve that, armor stands will not work.
The second question is, how do I add it to an NPC so that it will be like a health bar for 'offlinme players'. Using the scoreboard display health only displays 0 health.
How do I make it so it displays the ACTUAL health of the NPC?
No, armor stands do NOT work because teleporting them directly to the entity have a slight delay, unless there is someway to resolve that, armor stands will not work.

The second question is, how do I add it to an NPC so that it will be like a health bar for 'offlinme players'. Using the scoreboard display health only displays 0 health.

How do I make it so it displays the ACTUAL health of the NPC?