As far as I know, Acer laptops doesn't have this feature whereby
they will auto cut off the power when it is fully charged.
If you are using the laptop and charging it, you can safely leave
the charger on, though not recommended because prolong charging can
shorten the battery's lifespan. If you are not using the laptop,
but charging it, be careful. Some Acer laptops have been damaged
this way when the battery has been fully charged yet the owner
doesn't know. It overheats and damaged the motherboard.
For your 2nd question, you can use the laptop for very long hours,
but you better keep it in a cool room, because it will heat up
significantly in room temperature after a few hours. A cool room
will be able to keep the temperature down for a few more hours if
you intent to play for long.
