To be honest I havent read all the posts however I did buy one of those pcb drill motors in post 1 with the chuck, and I have to say its not that good, when you fit the drill in the chuck it wobbles around, the motor is ok but the chuck isnt good, its a one piece affair, I complained and got another sent that was as bad, the cutout down the centre of the chuck is way off on both.
I was going to build a drill press using an old microscope body.
I suggest if you want to do this that you get a 540 series r/c motor and you can get the mounting bracket for it too, and get a chuck to fit a dremel type tool, expo used to do a chuck that fits a 3mm shaft and is good quality, you might still be able to get one.