How can I prove them wrong if they always interfere ? (make a dual input)
JC can't be all that good
Now I must repeat for the third time :
my landings on average are just as good/bad as anyone else's.
How can I achieve the occasional greaser completely on my own (
an FO can actually land a plane on his own ) with some captains who leave me alone then other captains think they always must make a dual input to help me out like I am some type of cripple ?
if he has to resort to this nonsense.
What nonsense ?
Take a read of this extract from the Airbus manuals :
When the Pilot Flying (PF) makes an input on the sidestick, an order (an electrical signal) is sent to the fly-by-wire computer. If the Pilot Not Flying (PNF) also acts on the stick, then both signals/orders are added.
Therefore, as on any other aircraft type, PF and PNF must not act on their sidesticks at the same time. 
If the PNF (or Instructor) needs to take over, the PNF must press the sidestick takeover pushbutton, and announce: "I have control".
These captains are coming up with the nonsense to start with and doing something in deliberate breach of Airbus manuals.
Who is doing something wrong (nonsense) to start with ?
FO has every right to be concerned because clearly it is the captain who is doing something wrong here.
If I (the FO as PF) press and hold down my sidestick pushbutton (for not more than 40 seconds), it will prevent any dual input (as it is not encouraged by Airbus).
I would only do this to prevent any nonsense from the captain, which is a dual input
If the insecure and underconfident captain wants to take over control, he still can by pressing his sidestick priority pushbutton down. Isn't this the way it is supposed to happen anyway ? Press the button to take over control !
JC can't be all that good if he has to resort to this nonsense.
No wonder the Captain is concerned
I have not resorted to this "nonsense" yet (to counteract the Captains nonsense). I was speaking hypothetically. The captain has no wonder to be concerned.
Now if my captains are coming up with this nonsense, and I should not react with my own nonsense (as some say), should I report these captains now or just put with it (with their non-standard ways) ?
Frankly, if I was JC's Captain, JC would be PNF all the time
Maybe if you were my captain doing this to me, I would report you. Just because you are captain it does not mean you can do fly with own non-standard techniques.