Happy Turkey day to you as well.
I'd like to know who this breeder is and what city n state they are in???
Let me address the biggest concern right now, those joeys are wayyyyyyyyy to young to be separated from their parents ( unless they were rejected ) the very earliest joeys are weened is like 8 weeks old. Even if they were rejected by the parents they should NOT be sold until the are at least 10-12 weeks oop. In the mean time the breeder
should be hand feeding them until their bodies can handle a more substantial diet.
They are far to young to be eating a diet meant for joeys 8 - 9 weeks oop and adults. They should still be getting a animal milk based diet until at least 7 weeks when then parents and or breeder usually starts introducing them to actual food.
Responsible and reputable breeders won't separate their joeys from the parents until they are at least 10 to 12 weeks oop. The community crucifies breeders selling joeys any earlier than 10 weeks.
http://www.suzsugargliders.com/handraisingajoey.htm
Please go to that link and do some reading to give those joeys the best chance possible there is still a risk they may not survive. There is lots of info on the site so make sure to check out all the tabs she also sells joey rejection kits that has everything you need to feed them properly. You will also need a digital scale that weighs in grams to monitor their weights If I find a more accurate weight chart I will post it
There is so much information you need to know and I'm sure I will forget something since I don't breed. At this age the joeys are still riding on their parents backs to get to food and water and to get back to their sleeping pouch. You will need to make sure to monitor them so they don't get to cold. If you find them on the floor of the cage you need to get them warmed up put them next to your skin until warm. You need to make sure they joeys don't get dehydrated they are used to being fed every 3 or 4 hours at this age I think, if they get dehydrated they could have seizures. I am not trying to scare you, but there are just soooo many things that can happen that you are in no way prepared for hell I'm not prepared for dealing with joeys at this age.
In an emergency,
call Val Betts at:
806-274-9177
Val has a ton of experience
If your on facebook feel free to ad me I can give you a few more people that could be useful to you.
https://www.facebook.com/carla.sloan.1
As for all the other stuff, hamster balls n such ... no they are not widely used nor acceptable by the community. There are round abouts which are made secifically for gliders that are safer than hampster balls you can see them here
http://www.spinzoneglobal.com/Runabout_c_13.html
Sounds to me like the breeder is a touch out of date with what is acceptable and safe for gliders or the community already outcast her some time ago for her breeding practices ( which is pretty common even still)