Welcome to the forum and to glider parenthood.
First - you have had your 'problem' gliders for only a week. This is barely enough time for them to begin to adjust to a change in their entire WORLD - new cage, new sights, new sounds, new smells and new humans.
Give them some time to settle in to your home and to become comfortable with their surroundings before you judge their behavior. You would be irritable and confused if plucked from your home and dropped off in a totally strange place - like moving from a quiet country life to being dropped of in the middle of Time Square with no warning.
Gliders are very scent oriented and can be territorial as well. Some of the biting is out of fear of all things new - but it may also be a reaction to the scent of a 'foreign' glider on your hands.
It appears that you have already put all the gliders together in one cage. If you did not do gradual introductions and swap sleeping pouches and toys for several days to get all the gliders used to the scent of the others - they are just reacting to the presence of FOREIGN gliders in their space. Very often a female glider will be very happy to have a male companion but may be territorial when it comes to another female entering her territory. The younger female's fighting with the others is just part of the gliders establishing dominance between them.
If they are balling up and actually physically fighting with each other they must be separated immediately or they may do serious harm to each other. If they are just chasing and crabbing at each other - they will work things out between them.
Escaping the cage is not a glider behavior problem - the cage is probably not suitable for gliders. If you can post a photo of your cage, I can be more specific about the corrections needed. Here are some suggestions though. If your cage has wire spacing greater that 1/2 inch between the bars your gliders can just slide right out. If your cage bar spacing is 1/2 inch - then they may simply be opening any small slide up doors found on many cages and walking out. Another escape route favored by gliders is to slide the bottom grate forward and to then slip out behind the grate and exit through a gap between the grate and the cage pan found on some cages where the cage pan is not snug against the bottom grate.
Since you put mesh around the cage to keep them in - I suspect the problem is wide bar spacing. The best solution is to get a cage that has the correct bar spacing.
If you put mesh on the cage it needs to be attached to the INSIDE of the cage bars and zip tied at many points to prevent escapes. It needs to cover the entire inside surface of the cage.
Putting the mesh on the outside of the bars is DANGEROUS because the gliders can get between the bars and become trapped between the bars and the mesh.
One more consideration - If all of your gliders have not been checked by a glider experienced vet, a well check up and fecal testing would be a good idea. Sometimes glider behavior issues are actually a sign that they do not feel completely well. Fecal testing will let you know if there are any parasite issues that might need to be dealt with. Since you have already put the gliders together if any of them have parasites all three will need to be medicated.
Generally we advise a 30 day quarantine for new gliders being brought into a home with other gliders present. This allows the new gliders to adjust to the home before dealing with other gliders. Part of the quarantine is fecal testing at the beginning and again after 30 days to ensure that the new gliders are not bringing in a problem to share with the current gliders. This assumes the current glider has already been tested and is parasite free. Unfortunately, you were probably not aware of this part of bringing additional gliders into your home.