Bill_K Thanks for responding, but I would like some more clarification. You say the higgs field is uniform throughout space. That cannot be true, since, for example, an atom causes the higgs field to move around it like the meissner effect. Since the field does not travel through the atom, it must be unevenly displaced around the atom. An analogy would be a rock displacing the water around it, creating different pressure densities. The higgs field does not exist inside an atom. Next, according to wikipedia
"More precisely, the Higgs mechanism endows gauge bosons in a gauge theory with mass"
and
"The Standard Model of particle physics recognizes three kinds of gauge bosons: Photons, which carry the electromagnetic interaction; W and Z bosons, which carry the weak interaction; and gluons, which carry the strong interaction.[3]"
Your assertion that quantum chromodynamics magically generates mass for quarks is wrong, unless wikipedia is wrong. So, all gauge bosons are affected by the higgs mechanism, and mass is not created by qcd interactions. Also, you say that gravity does not couple to rest mass, which seems false. Two masses, at first, not moving relative to each other (meaning they are at rest), do indeed start moving towards each other, so at the first instant of rest, gravity would have to couple to rest mass in order to cause initial acceleration. Next, gravity doesn't always couple to potential energy. A mass further away from another mass experiences less gravity even though the two objects have higher potential energy.
To explain why the higgs could add additional mass for quarks inside the atom, even though the higgs field is moving around the atom, its the same reason why quark confinement occurs. Color charged particles in a gluon field could displace the higgs field, and create something that looks like the meissner effect, in effect generating mass. In other words, the glounic field probably has some interaction with the higgs field. However, because the higgs field does not travel through the atom, this means that bosons inside the atom can behave as massless, while also contributing to the mass of the atom.
The reason why people associate the higgs field with gravity, is because gravity is intertwined with mass. How is it unreasonable to assume that the same effect that generates mass is also responsible for gravity, since mathematically gravity depends on mass?