Somebody already has converted the Calculator for Mac, I'll try to find the link now.
http://www.thehiltons.net/nolimits/maccoastercalc/
I know it aint much, but why dont you give Tia an email and ask why? A member called RiscIt on CoasterSims converted the calculator to Mac, maybe he could help you out.
Back On topic, The program is great, no doubt about it but it does spoil the whole point of NoLimits. Before I enjoyed the challenge of creating elements with Hand and Mouse, not just a click of a button. Its a great learning tool, and I find it very useful if used with the Construction kit to export heartline paths. One flaw I can notice is that the elementary program uses so many control points that when in NoLimits, it gives such a messed up Track Spine its unbelievable. If your wanting to create a zero-g for inverts, change the heartline path to -1.