Could it not be the case, that the idea of hosting these events in the prominent new city centre hub that will be Liverpool waters, a stones throw from the centre for visiting tourists, with all of the cities major hotels there to house fans and athletes alike, is both a major selling point, and also a catalyst to get the whole thing moving if accepted?
And if that is the case, and the stadium on the docks would be seen as a wow factor centre piece, would it not make sense to put any additional cost of building a movable element into the design we have rather than build a 2nd purpose built stadium elsewhere in the city boundaries (stonebridge cross) that may or may not be used for other events in the future?
Bear in mind, not a brick has been layed on this stadium we have proposed, so it need not be 1 thing adapted for the others purpose as is the case for all of the other examples people have shown here (Man City, West Ham, Hampden Park). Any design elements that will allow the stadium to be purpose built for football and still allow for athletics, can be incorporated so that neither is compromised, with the additional cost of transformation falling on City Council.
If so, and our stadium is going to cost circa £300m, would the council be able to pay the extra £100m+ in collaboration, to have state of the art technology installed as has been shown in other examples (Spurs, Schalke, etc) whether than be movable pitch, move able stands, etc.
They would not then be left with an expensive stadium built perhaps in the middle of nowhere for the purpose of a 3 week event, but instead would host the event in a state of the art stadium in a prime location, which could also be used again for future events, all for the benefit of the city.
Just a thought like, but I'm not an architect.