Gas oven seems to be working, except for smell of gas and occasional in-oven flare
You either have a leak, or an air mixing tube is not aligned with the gas orifice feeding the venturi, or the orifice is wrong for your gas (or gas pressure).  check the alignment of all of the air-gas mixing venturi's.  Also make sure you have the right orifice for the type of fuel.  Also check the gas pressure.  If you have a malfunctioning pressure regulator, the orifice may be intermittantly getting the wrong pressure, and thus be intermittently delivering the wrong mix to the burner.  Check the pressure both while the oven is running, and when it is off.  If pressure rises when off, the regulator is leaking in the needle valve, if pressure fluxuates or is too high when it is running, there is some other mechanical problem with the regulator.