1) This limitation is owed to the way remote controls work outside of 
a gaming context. I.e. imagine pressing "right+up". While it makes 
sense in games, it might result in combinations of "first page" and 
"next page" actions as well as the mix-up of emulated keystrokes 
leading to combinations that could lead to undesirable effects in a 
boatload of applications. That's why currently, only one button can be 
pressed at a time. I continue to think of and refine a solution to 
this general problem, though.

2) The home button tells Remote Buddy to enter a special menu 
navigation mode. In that mode, the menu button (== B on the Wiimote) 
is always assigned to closing the menu. This way, you can map Remote 
Buddy's menu to any buttons - even those critical to navigation - and 
still leave the menu at any time.

3) There, too, is a reason why things are the way they are: many 
actions require the application they are targeting to be active and 
frontmost to operate properly due to the way they work.

4) Good point. I've thought of this some time ago, already, but have 
not come around to implement it, yet.

Best regards, 
Felix