Re. 'trespass without actually stepping on to the property' - the cases you quote concern people alledgedly doing more than just 'passing and repassing', which is all one is allowed to do on a public highway, plus anything reasonably ancilliary thereto! The cases you mentioned established that it is perfectly OK to stop for a reasonable amount of time to eat a packed lunch, take a few photographs and the like.
To re-iterate, it is perfectly legal, in England and Wales, for somebody to take photographs in a public place, even if the subject of the photographs is on neighbouring private property (i.e scantily clad on their own property)!
There are a few specific exceptions to this e.g. Official Secrets Act and Sexual Offences Act.
Also, remember that the legal definition of a 'public place' is very broad, and can, in fact, include private property, it is:
Anywhere the public, or any section of the public, have access, whether upon payment or otherwise, as of right or with actual or implied permission.
So a high street shop, for example, is a public place, as the public can assume an implied right to enter (until they are told otherwise, whereupon they would be trespassing)!