For the moving subject, you can give Rotobrush a shot: on a duplicated video layer ABOVE everything you've done so far... and DON'T try to use Rotobrush by just futzing with it -- you'll fail. If you go to AE help, you'll find Rotobrush learning resources.
Fore the static item, just make a mask around it on a duplicated layer, again over everything else. If the shot isn't static, you'll have to use the Rotobrush trick on it, too.
You need to set up a mask. Maybe this will help:
I used a solid to hide the text that was behind the wall. The mask in the sample didn't need to move but the technique is just the same. Rotobrush the obstructions and use them as a track matte for the 3D layers.
Thank you so much!
Thank you so much