Setting up 3x2

I'm setting up a 3x2 for my 318 1967 Plymouth. I have 2 8BA's for the sec. & a EBU for the center carb. I've read (I think) all the posts related to a 3x2 setup. Here's what my intentions are:

1. 7.5 PV for pri
   
2. 4.5 PV for sec
   
3. 57 jet for pri
   
4. 53 jet for sec
   
5. block idle circuit on sec
   
6. plug vacuum ports on sec
   
7. ctr carb supplies vacuum to vacuum advance
   
8. tweek choke plates on sec carbs for <.005 closed
   
9. pri carb only for choking
   
10. install choke plates in sec but fix in open position
    
11. extended shafts with prog ball bearing linkage
    
12. exact match for sec
    

Questions:

1. a couple or so articles said to dis-connect the sec acclerator pumps. Did I mis-understand?
   
   Why would you want to dis-connect the AP's???
   
2. If I block the idle circuits, do I still need air/fuel idle screws on the sec?
   
3. Do I need 5 deg or 12 deg throttle plates?
   

I know a lot of you have had a lot of experience with a 3x2 setup. So I'm hoping you guys chime in and review and comment on what I've written. This is new to me and I need expert and all comments. I would really, really appreciate it. Thanks.