Unless dampproofed or waterproofed, concrete won't stop water vapour movement. So that wouldn't be my worry. However, bonding new concrete to existing concrete is quite the art. And when you're investing in stamped concrete, it would often be prudent to start afresh with a new pour. If you're using ceramic tile, water vapour will move upward through the grouting. When I use ceramic tile on a basement slab, an uncoupling underlayment is a must.

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The biggest issue I have seen with alternative materials in residential construction is finding a contractor who will install them at a reasonable cost, especially in non-urban areas. I have used various precast concrete systems in commercial construction and have had three or four ICF buildings constructed, anything from basement walls to all of the exterior walls. If you can find someone to do ICF, I think they make great foundation walls. Environmentally, ICF is pretty benign, although some say there's a lot of embodied energy in concrete. I'm a big proponent of exterior insulation on a more-or-less conventionally framed house. The REMOTE wall system ( http://cchrc.org/remote-walls/ ) has a lot going for it. Now that some of the manufacturers of XPS foam are producing more environmentally friendly products, you can feel better about wrapping your home in foam board. Greenbuildingadvisor.com is a good site to get a lot of good info re: alternative design. Of course, site planning, orientation and layout are probably more important than the construction of the shell.

When we bought the house, as part of the negotiations, they had a Radon mitigation company come in and install a radon mitigation system. In the corner of the basement where the radon pipe goes down through the slab, they filled that gap about 2-3 feet out from the corner, but that's it. They filled it with some kind of grey foam, picture attached. It doesn't seem like there is a waffleboard sticking out or anything for drainage.