I'm working in centimeters because that is what UE4's unit scale is. My problem is when I scale a wall segment to be [304.8cm or 10ft] I'm no longer aligned to the grid properly. Am I going to have to scale my wall segment to be [274.32cm or 9ft] to stay aligned to the grid and just make a separate piece that is [30.48cm or 1ft] to get the 10ft the wall i want? The building I want to model is 30ft wide so i was attempting to make 10ft wide modular wall segments. I'm new to all of this so sorry if this question is dumb.
Just choose imperial in the unit setting panel. By doing this, the grid and all length system will give a proper behavior if you use imperial.
There is no different between imperial and metric. But if you want to cooperate with others, start in metric unit will be a better choice in my opinion.