the CFM issue is more vexing than it may appear
and is manifest in its fullest dimensions
here
I do like overclockers.com ('cause they post my scribbling ?), but the forums seem to be getting ever 'less experienced'
- now who says I can't be delicate ?
not too many WCers know too much about fans, and
certainly not enough to make even much of a guess about what the actual throughput might be
JD
your questions are valid, not all are so critical, and must in any case be approximated
many variables can be 'eased' into with a factor which could be added or subtracted as appropriate
(use a checklist: fan standoff - 1", 2"; restrictive grill - yes, no; etc)
our basic problem is going to be the data itself
I think a program using it is quite doable (focus on simple always)