Re: How do you keep your drawers in place?
Just a note on those pushbutton catches from Rockler -- we have the exact same ones on our coach, and they are a bit finicky to install and adjust, initially. You have to rout a slot or carve a recess in the frame above the drawer to house the locking bar, and you don't have a lot of length in the bar to work with. This means the drawers and slides have to be pretty exactly located, otherwise you risk not having enough engagement of the locking bar, and they will pop open if the frame twists or if you go over big bumps.
I had to shim a couple of our drawers to get them right. I'd love to find/make a top piece in metal to take the locking bar, that would simply screw into a cut recess in the frame and give you a solid hookup, but I haven't seen them anywhere.
As somebody else noted, the face frame has to be thick enough to allow you to cut the lock recess without weakening it too much.