As a builder that builds about 60-100 houses a year I built mine on slab. We used to build on crawl space but now only build slab homes, both monolithic and floating. Floating slabs look a little nicer since they are raised, but if cost is an issue it's much less expensive to build monolithic and just bring in a few more loads of dirt to raise the house site.

You are more likely to have settling issues with crawl space. They will most likely be minor, like hairline cracks in the sheetrock and doors no longer closing properly. Also moisture and everything associated with it like mold and mildew are more likely to be a problem.

As far as plumbing, use pex pipe run through the attic and a manifold. Pex isn't likely to burst as long as you don't have any connections in the attic. Home run each pipe from the manifold to the fixture. It will cost a little more, but it's worth it in my opinion.