回复：如何处理和老板的关系？

Ok, I feel I have to say something here...

Your boss has already shown you his answer by not responding to your (nagging) messages and that message is he either 他不愿做，或认为这点小事不重要. If you don't get it (worse yet get upset by it), it simply shows your immaturity, professionally. In terms of how you suppose to deal with this decision namely lack of adequate resource, it is your job to propose a more efficient process, or reduced deliverable, etc. and communicate that to your boss, in an effective way.

What I don't understand is why you can't talk to him or meet him in person, if you can't accept his answer on the subject matter. By insisting leaving a paper trail on everything, it realy creates distance and makes people cautious.

I would never recommend anyone to 越级向上反映, unless you are ready to start a war and leave the job.