Unless you are making a long run (~20 ft), use 3/16th. There are a number of threads on pressure balancing, but I just put 12' of 3/16ths on each tap and deal with a slower pour for low-carb beers.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk