8 years on the road full time and I have never had a cabinet door open. And All my drawers have some sort of lock mecchanisim on them where you have to lift up a little to open the drawer. Never looked at what it is all I know is it they have never opened.
Here is a plethora of options for keeping drawers and cabinets locked while in motion that are real simple to install.
I DO know that if you replace the microwave with a smaller one? IT flies clean out of that cabinet and crashes to the floor in a million pieces....on the first right hand turn you make! :B
Cabinet and drawer locks:
Child proof clips. Cheap and easy to install. Some you don't even have to drill any holes.
http://www.homedepot.com/b/Tools-Hardware-Safety-Security-Home-Safety-Child-Safety-Latches-Locks/N-5yc1vZc25f