Re: Pat Petrillo here!
Yes, I do think that some of those imagery things help young drummers at times..although it may sound a little cliche.."picture yourself on a beach with a drink dancing with a beautiful brazilian girl"...for instance, that may make you RUSH the tempo, instead of lay back, if you know what I mean ;)
In general, I am vibing on the other musicians, who help keep the tempo in the pocket...watch and feel them, and put yourself in the moment of the groove..When I first realized this is when I was playing with Patti LaBelle, and at first, I was real excited, and the guys were like, "Hey, it's rushing a bit"..and after I started watching their body language and things, I started to put myself into their zone, and it really helped me settle in.
Breathing wise, I don't think about it too much..It is pretty relaxed and normal. I don't find myself breathing in time, or holding my breathe at all..
except when the bass player is new ;)..ANYWAY..
Hope that helps!