Maybe I phrased it wrongly-I'll try again.
If you are asked to leave the premises, that would be legally correct, and you would have to leave.
However, if you are asked to stop taking photos, there is no law around to stop you, and the most that can be done is to file a civil suit gainst you.
Regarding the points about leaving the premises, trespassing, public nuisance etc are also correct. In a sense, you can be stopped from taking photos through all these means. But the very act of pressing your shutter button, cannot be stopped.
N.B. If you take photos of a private estate from a public place (eg a road), the situation becomes even more complicated and as far as I can see, the only thing that can be brought against you is public nuisance charge (by the police).
Agreed with you on the above.
With-regards to shooting a private estate, I take it to mean a private condo, residential estate, well as far as I know, except for a few residential estate whose residents are high profile public fig, ie: MM Lee, all else are free game. The property management's rights extend only to within their estate. You can take one step outside of their estate and they can't stop you. Unless the building is protected by law from photography, I doubt the police will want to do anything other than just asking why you're shooting the building, if they do came at all.
Cheers
PS: I think we're OTing too much already so we better leave this to the proper thread when it comes up.