It's because meat and dairy are kept separate at all times.
The correct term is 'laws of kashrut'. That being said, kosher kitchens have two sets of everything (pots and pans, cutlery, cooking utensils, dishes [some groups accept glass as neutral so just 1 set of dishes in that case], etc. Some people have two ovens, dishwashers, and fridges.
Many kosher kitchens are American.
The Double Tree cookies are actually made by the Christie Cookie Company and are certified kosher dairy. However, if they're baked in a non-kosher kitchen, they're no longer kosher. Some Double Tree hotels have Glatt Kosher kitchens so if the cookies are baked off in one of those kitchens, no problem, they're kosher.
Two kitchens
Jewish websites have information on commercial kosher kitchens
Everything is specific on how kosher foods are prepared.
Two requirements (there are many many more than just two) for keeping kosher are:Two sets of everything (pots and pans, dishes, cutlery, etc) - one for meat and one for dairy.A knowledge of accepted hechshers - symbols on commercial food products that indicate they are kosher.
Yes, sugar is Kosher. Everything that grows from the ground is kosher. There's nothing in sugar to make it non-kosher, as long as it doesn't come in contact with other ingredients, or machinery, used in non-kosher products.
If the kosher caterer in question makes wedding cakes, the cakes in question would be kosher.
Honey is kosher and some groups consider gelatin from non-kosher animals kosher because it is so far removed from its source.
By today's NEC standards, all kitchens are required to have to have a minimum of two 20 amp circuits.
There is no community out there with all kosher restaurants and you have to be very sure about if a place is kosher or not. These are just two of the millions of answers I could give you