Avoid checks to increase the speed of use of a function
Since the many checks in the different functions are quite often the code elements that require a major part of the CPU time, what about proposing a mode that skips all checks? This would be somehow (but not exactly, as we are not talking about compilation) like the Release and Debug modes of (gfortran) CodeBlocks.
I would see it as a check.mode argument in the functions, if check.mode == true we do as usual, and otherwise check.mode == false then we skip all of them. The recommandation would then be to do some tests with check.mode == true and then run the actual applications with check.mode == false. A vos risques et périls. ;)
Just an idea...