1) How far ahead or how many day's advanced notice is required for an order?
I have received bookings months ahead of events. The sooner you place your order the better.
Generally, minimum notice requirement for celebration cakes is 1 week and tiered wedding cakes is 2 weeks.

2) What's the minimum order?
Depends on designs. Generally, 1 recipe.

3) Do I need to keep the cake in the refrigerator?
Due to our humid weather it is not advisable to keep fondant/gum paste decorated cakes in the refrigerator. Only remainder after serving should be kept in the refrigerator for enjoyment later.

4) Do I need to keep the cake in an air-conditioned room?
No, unless your house is very warm and humid.

5) Can sugar be reduced in cakes and icing?
Sugar acts as a preservative, helps retain moisture, and keeps baked-goods fresher longer. As such reduction from cake will be minimal.
As for icing, sugar is the main ingredient in icing that gives texture and body to icing. Less sweet more fat butter cream available in bakeries are not suitable as a base for fondant covered cakes.
Reduction of sugar from fondant is not possible. You can remove the fondant and enjoy the cake with the filling and frosting underneath.