Are these significant factors?

For instance does a 6’-5” WR have an advantage over a 5’-8” corner, all other things being equal?

Same question on weight, does a 320 pound guard have an advantage on a 290 pound DT all other things being equal?

Does center of gravity figure into anything, like if I find a 5’-8” 220 pound RB would he have a higher likelihood of breaking tackles as compared to a 6-0” 220 pound back?

no, center of gravity isn't figured in... but heights and weights do matter