As far as I know, there is no native OS X model for XBox of any version. However, there maybe work arounds to making PC modders work on in OS X. Besides the commercial products that run Windows on OS X or making a Mac boot into Windows, both of course cost money, there is piece of software called 'Wine.' There are many off shoots of 'Wine' and from what I understand, 'Wine' can be "wrapped" around a Windows program and have it run in OS X. Of course, someone has to make this 'wrapped' application, in this case a very specific mod app. This may be difficult to find but may exist if there is enough demand for it.
In my guestimation, I don't think something like it would exist due to the Apple-Microsoft cold wars of years past. I'm sorry I can't give you a better answer.
Modding your 360 does not affect anything in a negative manner. Your original discs will work the same as they did before. -Personal experience from modding XBOX 360 for 3 years.
NOOBS
Yes especially online modding.
I wouldn't want to know because you can get a suspension from modding on Xbox LIVE
Modding is illegal on the Xbox 360 and therefore you will get banned.
Modding affects the console.
You can do it by modding your xbox 360. But it is very dangerous as virus can be transmitted through it.
Yes if not done right.
It gives you a console suspension from the Xbox LIVE Service. Where you Xbox 360 console will be usless where it cant be used anymore.
Modding is illegal.
Modding is illegal and you will get banned from Xbox permanently if caught.
Put your .dll on a usb that has been configed by your xbox and load it up, also works for aimbots so yeah... happy modding! :D