Under the EASA regulations, now in force, the two Certificates are 'Standard' and 'Public Transport'. You only require to hold a Public Transport Certificate for the carriage of paying passengers. So the old understandings are defunct.
I wish. You still need to operate and equip the aircraft in accordance with the ANO, even if it is now "a public transport aircraft" rather than "an aircraft with a public transport C of A".
What's perhaps worse is that with the introduction of EU-OPS, there is (from later this year) going to be an extra class aircraft in the ANO.
Commercial air transport aircraft are subject to EU-OPS, so they have to be excluded some of the provisions of the ANO. "Public transport aircraft" will now be all the aircraft that used to be "public transport aircraft" but don't count as commercial air transport for EU-OPS. And then there's aerial work and private as before.
So we'll live in a system that's even more complex until EASA takes over OPS for everyone and throws out the ANO provisions for all but Annex 2 aircraft.