Nice looking oven build! Based on the amount of research you have done, I am fairly sure you have seen some pics of my oven build in some old posts here. I can't add too much to the discussion but would suggest you not waste time mortaring each individual brick as you build the dome. If you go and find the Slice.SeriousEats.com photo gallery showing the building of the Donatella's oven in NYC by Stefano Ferrara, you will see he just pours on the mortar. I did it that way after individually mortaring a couple of rows in the dome. You have to move quick but it does a great job and takes almost no time in comparison. I did used a thin stick or something of that sort to force the mortar into joints as best I could. If mortar does not make it all the way down in between, no sweat. It won't make any difference in use.
Also, I used a stainless steel cable to control outward movement of the soldier course. I feel fairly confident that it was overkill since I could only get the cable sort of tight but have not seen any cracking of mortar that would indicate movement.