Transparancy, openess, and a willingness to address important questions, would almost certainly turn some sceptics into supporters
I include myself
You make it sound as if the McCanns are 'public property' Icab. They don't owe you any explanations, just as you don't have to answer to them. They are free citizens - no different to any other citizen who has never been charged with any crime.
The only reason sceptics want more ''transparency'' as they laughingly call it - (they really mean 'ammunition' imo) - is so that they can pore over every tiny little item, looking to find fault - which of course they will, even if there's no fault to be found. More information means more opportunity to make sticks to beat the McCanns with. It's as simple as that IMO.
As long as the Inland Revenue is happy with the accounts then so am I. It goes without saying that the taxman will have received letters informing him that the accounts are 'fraudulent' from some sceptics. As a result of that 'warning' from the public - the accounts will always be closely scrutinised - probably by a senior officer so that the IR are satisfied there can be no comeback on themselves. What more can anyone ask.
As pointed out previously a great deal of the money in the fund is their own, which they were not obliged to put in - but chose to. The fact that sceptics overcome this inconvenient fact of life, by completely blanking it out and never acknowledging its existence - is quite telling IMO.
May I ask what 'important' questions you are referring to Icab which you think would turn sceptics into supporters if they had an answer?