Nebby that bottom dovetail is damned near perfect, I doubt you could get it any closer.
A little tip for your finished product...After cutting and fitting the dovetails, take some 220 grit sandpaper and lightly go over the joint. This will fill any minor flaws or voids with fine dust the correct color. Then use a jersey rag (old T-Shirt) to lightly wipe down the area (no compressed air here obviously). Take a can of spray lacquer and very lightly spray over the joint from about 12-14 inches away. Just a very light touch, and if you have no lacquer around hair spray will substitute well as long as it's the aerosol type. Give that time to dry and very lightly sand with 400 grit. This won't interfere with your chosen finish, and will give you a perfect joint.
Your box plan seems reasonable to me.
Give me a powertool over handwork any day! As long as new tools are invented to speed up the woodworking process, guys like me will keep buying them. I have great respect for the woodworkers of the past, but we gots 'lectricity now baby!