Hi The least you should do in your case , is use liquid Waterproofing Membrane ( look at your local flooring supply store) it is kind of heavy and shipping cost will be too high, What I would recommend you to do is to mix a scup of no 20 or 30 sand with a 2 gallon of the liquid Waterproofing Membrane, it should give you great protection and easy to apply tile on. A product I am familiar and recommend is pro red by c-cure ( link to c-cure pro red attach) I would not recommend sheet membrane, you will need to know how to use it in/out side corners and overlapping and making sure it seal well., a risky way for leaks. The liquid apply same as you paint 2 heavy coat will do the job. Never heard of Hydraflex, I will check them out Here is a link that might be useful: C-Cure pro red

My greater concern here would be "Dynamic Pressure" which is the working pressure under flow. This bathroom is on the third floor so if this structure is on slab the vertical rise from the water main to the shower mixer will be approximately 24' and with a basement it could be as much as 32' or perhaps more. That would be a 10.3 to 13.8psig loss to vertical head. While the code required minimum dynamic head pressure for a standard shower mixer is only 8psig a temperture controlled shower mixer is required a minimum 20psig dynamic pressure. This means you would need between 30.3 and 33.8psig dynamic pressure at the main under full flow.

Hillside House...yup, you were the originator on that idea! Partim...sorry, i really wish this forum had numbered post for easier reference. In the black and white floorplan posted above (11/12) is what i was referring to. Basically keep our current stove/oven where it is but take out the 2 walls of the pantry and put the fridge there. Kathi Steele...what "bank of cabients" are you referring to? Which "doorway" are you referring to? Since this remodel has rendered by unable to focus and therefor useless at work, i've been messing around on IKEA's design program today. So basically, this is the new layout i'm talking about with putting the fridge in the current pantry area (the software would not allow me to put a doorway to the right of the fridge shown below):

The first is to consider what the value of your home is and the comparables in the neighborhood. Determine your equity next and the cost to renivate. Then think how long you plan to stay in this home or would it be wiser to find another home that suites your needs? Alot of things to consider that impact this decision. Best wishes!