They're adjustable for accuracy (or they used to be anyway). As you tighten the screw the blade nestles against two raised 'lumps' at either end of the stock channel. Should the square not be true, a stroke or two of a flat needle file across the offending lump will help to correct the issue.
I have a Milwaukee 12v with interchangeable heads but it's the T grip version with hammer action drilling as well and the forward/reverse switch is exactly where it should be - by my thumb. It's a great little drill - the heads are easier to change than its predecessor and the chuck head will...
The first time I came across exterior MDF was 30 years ago when it was the main cladding material for the Orangery at the British Garden Exhibit in the 1992 Floriade. It was being hailed as the ultimate shop fitting material and known (to us at least) as Medite.
Not correct. The majority of inset hinges require that the plate that fits on the carcass is set back to accommodate the thickness of the door (which is of course variable) therefore 37mm plus the door thickness. I assume you don't have much experience of fitting these hinges.
What about the doors meeting each other edge to edge? An overlay door has 2mm gap to the edge of the carcass which means for an 18mm carcass, 16mm is covered by the door. You couldn't then hang a door off the other face without the doors hitting each other.