My house has a concrete slab floor and the shower drain sticks up about 3/8" above the level of the slab. In addition I am planning to have a cultured marble shower installed and I have a couple of questions:

1. The cultured marble shower dealer says just put the PVC membrane directly on the slab floor. They also said the bottom of their pan is flat and the top is sloped. This doesn't sound right to me since I would have a "pool" for any water that leaks past the drain to collect. It seems to me I need a concrete base at the level of the top of the drain and then put the membrane on top of this. Who is correct?

2. Assuming I am correct on # 1 above, what type of concrete should I use (e.g. floor leveler, portland cement, etc.)? Also do I need any additives in the concrete?

3. Also assuming I am correct do I need a slope to the drain and if so is 1/4" per foot OK or should it be something else?

4. I have purchased a "perfect curb"... kind of a wire mesh that sticks out 1/2" above the curb and on the sides. Do I just use mortar mix on this?