I like your answer. For me though, I come from the point of view of one who sings regularly in the choir. In this circumstance, things like brushing teeth and even drinking water or other things (and then of course not partaking of Communion) are necessary to provide that joyful noise and leadership for singing. As one who has the gift of singing, I need to be able to perform and there are physiological needs to do this. Physically speaking, if you are not serving or singing (i.e. a Joe Schmoe parishoner), you pretty much just need to be able to crawl to the Communion line, sacrificing all other bodily needs (food/water). But if you are singing/chanting, then there are different circumstances. I really haven't read of any "accomodations" per se for those that sing/chant.
(Sidebar: 10 years ago, while still in college and attending a small mission, the priest, during a Presanctified, fell to his knees about 2/3 the way through the service. He recovered, served Communion and was subsequently fed, but it was a scary event. He was not young (late 50's or early 60's), but fasting for Lent as well as taking High Blood pressure medication. The paramedics were actually called and waited outside. As much as we need to stress fasting, we also need to take medical conditions into account. This priest, while well intentioned, should have eaten and drunk something around noon at least to avoid this happening, but ce la vie.)