Anthony, you will have better control with a gate valve, you will be able to more precisely adjust the air and be able to find that exact spot each time. If you had put your gas input down somewhere in the vertical run you will get better mixing.
I run my forge about .5# pressure. I weld Damascus billets without flux. You can adjust the atmosphere in the forge just like an oxy/ace torch. Adjust a little gas, adjust a little air until you get the atmosphere you need. For general forging I want a natural flame and it is quiet, for welding I want a reducing flame with about 6" of dragon's breath.
Let me know when I can help you again.
Wayne