Will using your Memory Module in my radio break my warranty?

No, it will not - this is coming from Futaba. On a side note, don't confuse the CAMPac slot in your radio with the frequency module port on the back. Using a frequency module that is not approved will not only break your warranty, but it's also against AMA rules and you are flying uninsured.

Is there any difference between the Hansen Hobbies 256K Memory Module and the ones Futaba sells?

The 64K and 256K modules have special microcontrollers for proper operation whereas Futaba uses a custom chip for their 64K. Functionally, there's absolutely no difference between Futaba's product and ours.

I've heard that the 64K modules have longer load times than the 16K's and therefore shouldn't be used in the 8U and 9C...is that true? (this question applies to the 256K since it is split up into 64K banks)

This is something that Futaba reps have been stating in internet forums and such, and it simply doesn't make any sense to make such a claim. The 64K module will take longer to initialize (the radio initializes the memory the very first time you use it) than the 16K, but after that there is no "load time" difference whatsoever. FYI, it takes the radio about 2.5 minutes to initialize a 64K module. The module only has to be initialized once and then it never has to be done again. Every time you select a model from the module it has to load that data - this takes a fraction of a second and 64K's don't take any longer than 16K's - they both use the same addressing scheme and data transfer takes exactly the same amount of time. Basically, the first time you turn on your radio with a new 64K, you'll have to wait a couple minutes for it to initialize, then after that you'll never see any difference. When you select a model - you push the button on your radio and the data has been transferred before you even lift your finger off the button - if that's a long load time I'd like to see a fast one!