Cant remember if these things go in front or behind the tabs inside if the fender.

The side tabs on the gusset panel go behind the lip of the fender. Or are you talking about something else?

The rubber j shaped piece that fills in the gap between the bumper and fender. If you zoom in a little on my pic you'll notice i got it on the back side of the metal fender tab. I couldnt remember if it went that way or in front of it. Also what is the gap supposed to be going across the bumper where it meets the hood and fender? Im trying to get it to fit as close as i can but the hood keeps coming in contact with the bumper.

Here are a couple of pictures if that helps. Bumper and fenders have never been off the car.

In front....the originals on mine were rolled over from age to almost cover the bolt head.
Not in place with the nose fender, but you can see the rusty spot from the front of the tab on the back of the filler. Note the curve "in".