No, they eat totally different things, and if they ate each others, they would probably become very ill and die. I know this from experience...
no
No its not, i guinea pigs cage is way bigger. & you should not have the same size of guinea pig cage as your hampster.
Yes
you shoudl not put a hamster and a guinea pig in the same cage no matter what.
Yes, i bought one Guinea pig and added another around the same time, and they get along great.
Yes,you can keep her female cagemate with her unless the cage mate tries to harm the baby.If she does that you will have to keep them separated at least unti the baby is older.
you could put another guinea pig or they would probably get alond with hamsters or bunnies
This is not really a custom cage, but a cage with homemade penthouse on the top. http://www.guinea-pig-paradise.com/homemade-guinea-pig-cages.html
I have a guinea Pig and I've never heard of putting a chick in the same cage with a guinea pig, but I would say its okay for now, like when there little, but you should know that older chickens will catch mice if they were able to. And chickens may mistake a guinea pig for a mouse-there not the smartest animals in the world.
It depends. They certainly wont be aggresive, but if you do, make sure to spay and nueter them.
no
I try to clean my guinea pig's cage around once a week or when it looks dirty.