Ah yes, Venting. I tied my sewer pipe into my pre-existing vent pipes. Also, the grey water tanks are always left open and running, which is also tied into the sewer pipe, like it was before. There is venting there as well.
As for the 90 degree angle fitting, no problem. I assumed that since the bull run valve was originally made for outdoor septic systems, it should work for my system. The bull run was made to be installed underground & horizontally. So, I figured that by placing the valve vertically, I would get a better and stronger flow.
Like I said. All works great. No smell, no gases and all poop runs downhill!! :-) Hoping that the idea may work for someone else.