Is it viable that an abductor would remove a key, get it copied and then put it back? I think that is too risky.
Yes; quite a viable proposition. Happens all the time in burglaries all over the world.
Were any keys reported stolen or missing? Did anyone come forward in PDL to say they had copied a key like this one (which appears to be very distinctive)?
None of us can answer those questions as we were not the police doing the original investigation. As for any locksmith voluntarily coming forward to say he had copied such a key, probably unlikely - we have been led to believe that there is a distinct uneasiness among the Portuguese populace to fully trust the police. Such an attitude is not confined to Portugal, however. Many people don't wish to "become involved with the police." So no - I don't expect anyone to have volunteered that information, but I do wonder if the police even asked the question of the public.
So are you suggesting that the abductor watched the Mccann's after their arrival and decided he must use a front door key if he wanted to abduct their child?
In that case he had what 4 days, to note the McCann's were there with children, then note their night time activities and leaving their children alone, find out where the keys were kept, take one without being seen - and run the risk of not knowing when the keys might be used thus potentially alerting MW staff to a key being taken, then get one copied and then put it back, again whilst not knowing when or how often the keys would be used or checked?
They did not need to go to the police. Given the McCann's have had their own private PI's for the last 6 years on the case one would presume that this is an area that would have been given much attention in their work.
So why haven't we heard of anything concrete in this regard?
You would expect the PI's have to have released either that info to the media, or indeed passed it on to the police, wouldn't you?
Equally the UK media has had an insatiable appetite for McCann related stories, do you not think someone with a key missing or had copied a key would have come forward to take Murdoch et al's shilling?
Can you imagine the splash in the UK papers had someone been discovered who had lost their key to 5A or someone who had copied a key just like it, thus validating the McCann's story?
It is inconceivable to believe the McCann's would keep such a key piece of evidence, which supports their claims, quiet.
How many burglaries around the world have the same level of media spotlight on them as the McCann case?
I think it is eminently viable, indeed probable, that had such a scenario unfolded someone by now would have come forward to admit having lost a key or cut one like it, and given the media's interest in the case and support of the parents, it would have been reported in the press.
Despite the doubts you have i would also think that if such evidence was presented to them the PJ would have no choice but to reopen the case if such evidence was in the possession of the PI's or the media.
Given we have heard nothing in this regard it must be safe to assume no one has come forward becuase a key was not taken.