Gerbils normally range from 4 inches to 6 inches but if you buy the new gerbil stretching rack as seen in The Princess Bride on www.imsoangryatthisquestionicantseestraight.com then it is possible to make your gerbil up to 1 foot long!!!
Gerbils can suffer from heat exhaustion if you handle them for a prolonged length of time.
They vary, most gerbils grow to 4-6 inches (10-15 cm) long [not including the tail; up to 12 inches including the tail]. Great Gerbils, the largest gerbils, grow up to 8 inches (20 cm) long [not including tail; up to 16 inches including the tail].
You can give them different chew toys for them to chew on and it should keep the teeth at a decent length.
Other gerbils.
Gerbils are an animal and can not be "invented".
Male gerbils can be neutered, but it is not recomended. Female gerbils should not be spayed. In general male gerbils should not be neutered unless there is a good reason for it.
Yes, mice are smaller than gerbils, but I think gerbils are the right size.
no gerbils are not originally from the UK but instead from the deserts of Asia. But you can still buy gerbils in the UK
They do have seizures (this is common in young gerbils)
No, they are not related. Gerbils are rodents, Rabbits are not.
No, Gerbils are vegetarian.
Gerbils and nothing else.