Without a dryer the moisture in your air lines will freeze and by only running a heater a few hours of the day the floor will always be cold.
The dead air space in the walls isn't great but best with sealed walls.
My neighbour acquired a set of crossing lights and wants me to wire them as I have already installed them on her tree in the yard.
They use 12 volt automotive bulbs which I can step down using a transformer from 120volts ac.
I can use a car flasher but my real issue is making them flash back and...
lilredex has it figured out, you won't get curls as it will only chip out ( I drill it dry).
I make a rectangle and screw it to the wall and have angled straps (1" x 1/8 x length needed)
welded to the front and angled to the wall and cut rough pine or plywood for the insert (shelf).
I would drain the oil then put some varsal in the sump and shake the mower side to side and drain.
Add your oil, run and change your oil again.
Like Leaflessshadetree said get your engine hot to avoid condensation.
I like your charging station, my thoughts are to screw it to the wall near an outlet as you have and make a bail wire similar
to a rat trap less spring that would drop down to a stop so you could charge batteries right on the wall.
I bought my tank quite a few years ago, when I run out I go to the same welding supply shop and they exchange
for a full tank and pay only for gas.
I leave my empty in my vehicle so they can see I didn't just grab an empty from just inside their gate.
They handle the empty faster than me...
My shop is roughly 700 sq. ft. x 8 ft. high.
My wood stove is a Pacific Energy "super 27" and takes a stick of wood 19" long straight in.
There is always wood for the taking in my neck of the woods.
I don't mind spending money on decent tools so the initial cost of saws, splitter, trailer...
For security reasons your door should swing inwards (pretty easy to knock out hinge pins),
I like ybnormal's ideas and get a roof rake so you can bring down snow before it builds too high.