OK-- Will try to answer as best I can.
#1-- you will have to try each size cap to see which will work best. Best solution is to get a set of nipps from Thunder Ridge- Treso brand. Then #11 will work.
#2- the screw is there to keep the wedge from falling out when you are taking the barrel off. Wedge won't "wear" & the screw is either in tight or it is loose.
#3- the pins are there to set the hammer on originally if ya loads 6 chambers. Pull hammer back & stop b4 it gets to 1/2 cock, turn cylinder till the pin lines up with hammer, let hammer down.
When you seat the caps, use a push stick to really seat them on the nipps. I prob would start with #11's. They will fall off (shot ones)as the cylinder goes past the frame.
If ya needs any more info- let me know. I shoot nothing but C&B for 2 1/2 yrs., 3 matches a month, and have 18 of them.