Here's my set up.
My only dog in this fight is that I have a natural gas outlet on my house. I only use it to boil seafood or make jambalayas.
As mentioned the natural gas coming out of your house is only 16 oz. of pressure. You need more than that. The problem is with your regulator not the orifices. Propane orifices are slightly smaller than natural gas. Just buy the coversion kit and run with that.
As far as the hose you have and the single hose clamp that's not a problem either. The pressure isn't that high to worry about that. I would just be wary of that thing sticking out so far. I used a 2" nipple and hooked threaded it into a t connection (directly on the other side of that wall is my dryer) in the wall. Then I added my valve and a chicago coupling. Sticks out about 6" total.
I also have a piece of hose about 15' long with a 3/8" stainless pipe with some holes drilled in it that i use to light coals and small fires.