TELEPORT RESTRICTED OBJECTS
For completeness' sake I will talk about how teleport restrictions should be applied to objects - even though the only planets that have objects on them are the few where I have designed custom objects for the PO, and the even fewer where the POs have been allowed to write events in order to test the editors!
In general, most objects should be teleportable. Since objects are now persistent, we encourage people to hang onto them, so we don't want them to stop anybody from using a porter. The exception is puzzle items. Just as I don't think it's a good idea for players to port around a puzzle area willy-nilly, I also don't think it's a good idea to port around while carrying pieces that are vital to a puzzle. That particularly applies to objects like keys or other things that give access to a certain area, or to objects that are intended to be contained to a certain area and not used anywhere else, and which are taken away by an event when you leave the area. For example, on Graveyard, if you go back to the LP any objects from the planet that you are carrying are removed - since some of them are pretty icky (rotten corpses for example).
An example can be found on Diesel's roof garden - the fireworks. Normally, you can't take them downstairs into the bar; they get confiscated by a waitdroid. That's because the message you get when you set one off talks about it flying up into the sky before it does its stuff, and that makes no sense if you let one off inside a building. So if you can't walk off the roof with the fireworks, you shouldn't be able to port away with them, either!
Admittedly, there's a bit of overkill in making the fireworks teleport restricted - after all, the roof garden is teleport shielded so you can't port away from it anyway. Still, nothing wrong with taking extra precautions.