I would like to hear from the higher ups (E-8/9 and O-3+) about professional perception. Is there a point where it is too much?

looks and sounds Like the Chief needs to get a Grip...
Unless he is going to have someone relieve the Gate Guard periodically to make chow runs or bathroom Breaks... looks like its the Chief's who has the problem ...
and the Moron sticking his Nose in some one else's business... what does it matter if the gate guard gets chow delivered...
Are their regs covering the issues...
any decent NCO or Officer of the Guard would have the Guard Posts rotated regularly to make sure the Troops are taken care of...
There are 2 things the all NCO's and Young Officers need to remember...
1... Accomplishment of the mission
2 ...health and welfare of the troops
3... with out 1 + 2 you are screwed... or as an old SGM used to as Look for a new Job son... I don't beed you here...

Why is it that anyone even pays attention to some idiot minding someone else's business ? A lot of other people can eat whenever they want, the Security Police don't always have that mobility and if the Chief didn't support His own men shame on Him ! I find that response from a senior NCO or Officer disgusting and I'm glad I never had to work for anyone like that! As a Senior NCO (now retired) myself the individual minding someone else's business would find out very quickly it wasn't a good idea !

In situations like this, ask yourself two questions:

Does this action contribute to mission accomplishment?
Does this action take care of my ______(Soldiers/Sailors/Airmen/Marines)?

If you answered yes to these two questions and your action did not violate a constraint placed by a higher commander, you should be fine.