Craft and Mg. Craft DO impact things, but it's... difficult to use. Basically, craftmanship and magic craftmanship impact chance of success, and how much progress is gained. The problem is that every recipe is either governed by physical, or governed by magic... and there's no clear way to tell beforehand whether a given recipe is one or the other. There are rules of thumb out there, but there's always exception to every rule.

Best way I've found, is simply to use up to date gear that's DoH focused. If all your gear is roughly the same level, you can expect to get a fairly even spread across all three stats. Then just stack your main stat with materia, and eat fish for added control (Control reduces destabilization by the way).