This posting is older than 6 months and can contain outdated information.
Yes, you can control Keynote presentations using the Apple Remote. If 
Apple feels you have the right Mac for it (i.e. this works on my 
MacBook Pro, but not on my iMac Core Duo). But - without Remote Buddy 
being active - the Menu button always will make Front Row show up.
I repeat: Remote Buddy does not, can not and did not alter the 
default behaviour of the Apple Remote on your computer. It contains 
no such code nor would I know of any way to achieve this. Apple 
Remote default actions are hardcoded in Apple's rcd.app, which seems 
to send messages and execute AppleScripts to achieve the default 
behaviour. It is a system background process and as such there is no 
way to alter the way it performs without patching it - which would - 
by the way - require root rights. Which means, it would have to ask 
you for permission. And then, there is not a single reason why Remote 
Buddy would want to patch that system background process.
Right now, you can't customize which button opens the Remote Buddy 
menu. This is planned for future releases, though.
Best regards, 
Felix