Ok for the objects, I'm not too sure about that...
But for the portal what you have to do is go into map maker, load your map, and then go to the tab that's labeled "Map".
Where it says "Has Portal", check that box and then under that it should say "Destination Position".
Then what I do is, put your cursor over where you want your portal to be(make sure you're facing the same way you want to come out of the portal), and at the very bottom of your window, it should have a bunch of numbers, copy those numbers down.
Now, in "Destination Position" for 'X' put down the first number from the bottom of the window(all the digits won't fit but just get the 1st 6 digits down)
For 'Y' put the 2nd number from the bottom of the window
and for 'Z' put the 3rd
And for 'Arrival Yaw' put the number from the bottom of the window that was next to the word 'Yaw:'
Sorry if this is confusing, tell me if you still need something cleared up
Good Luck!