Looks good to me if you're using 240v feed. You'll be drawing around 20 amps or a little more so go with 12-10ga. for the element circuit. I've purchased two similar controllers from Coldfusion and he's quick to ship and both worked without flaws. I also noticed he lowered his shipping charges.
One inch of insulation is a little skimpy but few home range ovens have more and some will hit 500 or more degrees. I would be sure to maintain some clearance around the oven though. Also, air insulates about as well as any filler so a multi-wall oven can be just as efficient as one packed with fibers.
A fan is good because it can even out temperature variations within the oven. Hot spots will be near the heaters and at the top. Drawing the hotter air from the top and getting it back down to the bottom helps balance temperatures. Another option is to draw heated air from near the elements and vortexing it through the oven. Even the smallest ovens gain consistency with forced convection. It also helps the thermocouple, hence controller, to react to temperature changes faster.