Validity of ionic resonance structures What's wrong with ionic resonance structures? I asked one professor about them once and all he commented was "I've seen them too, and I think they're wrong." 

Another professor rejected an ionic resonance structure showing the "H+" ion and asked me what phase the experiment was run in, in an attempt to figure out why the authors reported a resonance contributor with a H+ proton. He specifically asked if the experiment was run in the gas phase. 

I think this guy forgot what resonance structures are because I know that he emphasizes that bare protons do not exist in solution, and he was probably thinking about how there could be a bare proton shown in a resonance structure if the molecule is in solution. The resonance structure I showed him was this (which I could see him picturing in solution, given that it is nitrous acid. 



However, resonance structures are not discrete forms of the molecule in question - they're just contributors and show that there is partial ionic character; that there is a highly electronegative atom that is withdrawing electron density. 

So I ask:

1) Are ionic resonance structures valid?

2) If so, why might they be valid, or what counterarguments might you present to someone who argues they are invalid?
I can't imagine anyone arguing that ionic resonance structures are invalid.  The often contribute significantly to the structure of a molecule and help explain the various physical aspects of the molecule.  The following ionic resonance structure contributes significantly to the description of the carbonyl compound.  $\ce{NaCl}$ is not totally ionic and is described by a blend of both the ionic (major) and covalent (minor) resonance structures shown below.



Resonance structures with a positive hydrogen (proton) are important in explaining hyperconjugative effects.