Congrats on pursuing this. The problem is a worldwide one, and revolves around the issue of private space masquerading as public space.
Melrose Arch has been particularly succesful in creating the illusion that it is a public space with high streets and piazzas and permeability and other good urban design things, but it is in fact a gated and very private community of the most insidious kind. In this case I think they could have refused you permission, but I am glad you requested your ‘permit’! I have been challenged for photographing on the streets of Rosebank by their so-called business management district self-appointed guardians of the peace! I pointed out that it is not illegal to film in truly public spaces, and the guard backed down (although he maintained that he was concerned for my safety whilst publicly using a camera). I have also been challenged for photographing a tram station in Dublin – from a public street, but they maintained their station was a private piece of property! I made the case that their private property was on public display and so long as I did not photograph their private asset from what they believe to be the private ground of their station (which I strongly dispute – I am sure they only have a leasehold use of public space for private income generation) they could pipe down.
As long as public interests (like city councils) do not provide truly public spaces for the public, this gap will be filled by private enterprise creating pseudo publicness where they can effectively create and defend their own feifdoms.
And btw, I agree that a cinema would have been nice in the new phase!