The biggest thing to remember here is that end grain will not hold glue, which is why mortise and tenon joints are the way they are. They allow a large surface area that will hold a glue joint well. The rest of your questions will depend greatly on the type of tools you have. By drilling machine do you mean a drill press or just a hand drill? Is your smoothing plane a low angle block plane or a regular #3 smoother? Is your hand saw a traditional cross cut hand saw or is it meant for ripping?
1. Assuming your smoother plane is a regular #3 smoother I would not suggest using it on your end grain. Usually low angle planes are used on end grain and even then they are prone to tear out and chipping. I would suggest getting a miter saw. My Skil miter saw was a little over $100 new and I use it constantly. I good smooth and perfectly perpendicular end is a 100% must with nearly all wood projects.
2. Since here you are attaching long grain surface to another long grain surface glue will hold these pieces well, but probably not well enough to support a mattress and two people so you could reinforce it with screws or even wooden pegs.
3. Since the feet are also long grain to long grain the same principals apply, but since there wont be any force on those except for pushing them together you could probably get away with just glue as long as both surfaces are very smooth and flat.
4. The joints you have here are great joints to be reinforced with pegs. You can easily find large ½” to ¾” dowels at any hardware store along with a drill bit of a matching size. Just drill a hole down through the middle of the joint, put some glue on your dowel, tap it into place, and cut off the excess once its dry. If you would like a temporary joint since most beds need to be disassembled to be moved you could use carriage bolts or even bed bolts.
I would suggest looking at the free build videos for the wood whisperer platform bed. His design and materials are different but the concept is the same.
I am actually working on a very similar project right now and will be using a sheet of plywood to support the mattress. I pride myself on not using the stuff so it wasn't an easy decision but it is needed. hope it all works out for you, and good luck.
Last edited by GISer3546; 08-29-2014 at 10:09 AM.