Here is the trick: Take your phone and change the ALARM volume all the way to 0, or whatever volume is acceptable to you. If you just put your phone on silent, it doesn't affect the alarm. The alarm volume is what the camera uses for the annoying focus beep. There is probably a setting too that when you just put your phone on silent, it will change ALL your settings, including the alarm, to silent but I don't have that info right this second. I'm sure there is a way though.
To disable your dial pad sound, just go settings--sound--audible touch tones--uncheck.