Subject: spin value and energy requirement for quantum field?

1)Does each field have spin and the energy from the spin even if it has no real
particle? Such as: electromagnetic (non-zero spin, zero field value with no real
particle(=photon)?), gravitational (non-zero spin? zero field value with no real
particle?), Higgs (zero spin, non-zero field value? with no real particle),
gluon, electron (and other elementary particles) fields etc.

2)What is the (minimum) energy requirement for fermionic field and bosonic field
to exist accordingly?
Does spin 1/2 field contain more energy than spin 0 field when they contain no
real particle with least energy?
Does spin 1 field contain more energy than spin 1/2 field? if so how much?
twice? Does spin 2 field contain twice more energy than spin 1 field? What
determines the minimum energy(=frequency of wave?) required for (ground(least
energy) state of) any field?

3)Why photon&gluon must have spin 1 but cannot? have spin 2?
why graviton "must" have spin 2 but cannot? have spin 1?

Re: spin value and energy requirement for quantum field?