Rocket Oven BBQ

I'm looking for some honest advice.
I have this design for my new rocket oven i intend to build in my back yard. i want it to be as efficient as possible so i will try to have good draw, good heat transfer to the oven, and good insulation.

I would appreciate any thoughts in terms of design and dimensions from those more experienced. I have not built a rocket stove before so this oven seems adventurous.

vertical feed tube.
horizontal burn and jtube.
adjustable side air intake and access for ash removal.
well insulated with either vermiculite or fiberglass insulation.
baffles around the oven to maximize heat transfer.
i calculated the air flow so that it remains roughly equal from burn pipe, around each side of the oven, and then out the top.
ive drawn and insulated door but would ideally like to change to a glass door.
oven is essentially three barrels. inner barrel with two cook levels, second to form the baffle for hot gasses around the inner, then the third to surround the insulation. (pictures show the outer barrel partially cut away)

outer barrel is a 55 gallon drum. so 61m diameter. 5cm insulation. 5cm between inner and second barrel. 150mm stove pipe for the feed and burn chamber (insulated).

i will build a separate simple smoker and grill next to this within the same unit.

Hi Hamish, lovely design; I'd say it does look a tad adventurous, but nothing ventured, nothing gained, of course. My feeling would be to ease yourself into this; if this is your first rocket construction, see if you can get it rocketing well before you put the oven attachment on - maybe use a temporary vertical pipe in place of the oven. The critical part of all this is going to be your burn tunnel, and a bit of experimentation always helps. Hope to see some videos of it in action soon