I would always use rebar for something like that
You will need to wait 24 hours before installing a waterproofing membrane on this product.
Concrete currng is a complex chemical reaction too difficult to explain in this format, Basically, 1 you want to control the amount of mix water, this is called the water/cement ratio. This is critical in strength and workability 2 concrete cured at 28 days. It is good practice to control the moisture in the concrete curing environment. By keeping your concrete wet, moisture cannot evaporate out of the concrete. You can seal the surface of fresh concrete with liquid sealers to control moisture or cover with plastic . Keep your project moisture controlled for 1 week. 3. Lastly, concrete curing is a exothermic reaction Typically small homeowner projects are not large enough to require heat control. You, can refer to the Portland cement association for more info.
Yes this is a good material for this project. It is fine grained and will hold surface features if used in a mold. Remember that it sets up fast so mix small amounts.
1" is Ok for the thickness. Instead of "gluing" I would pin the new slab to the brick by drilling in Tap-Con or cement screws protruding 1/2" upward into your new slab. You'll need a hammer drill to drill pilot holes into the brick. A drill bit is usually included in the package of screws. So, 1" screws drilled 1/2" into the brick and extending 1/2" into the new slab. A Cement-All slab of that dimension may crack. I would rather use tile as a new top layer.
my silicone mold is 1/4 inch in thickness and about 3.5 inches tall
Yes just know that it starts thin but sets pretty quick. Clean with spong to leave a good finish.
Really an overkill. But it should work.
Yes it can be applied vertically. Make the mix stiffer than usual (less water) to stop it from sagging. Wire mesh or concrete screws behind the repair will help. Remember that this material sets up quickly so mix only what you need for the repair area. I do not add flow control for vertical applications.