Quad Junctions. Why are some not working the same as identical looking one nearby? NOTE: as per Moonboots helpful suggestions. Here is the .Blend file for this problem:   

Hello all I am trying to learn Blender. I've read lots and watched lots of videos and kinda understand the need for Quad Junctions to 'steer' the edge loops to make sharp edges in the model etc.

I'm currently trying to make a fairly basic car bonnet/hood. It is almost all flat, except there is a vent in the middle with a rim running around it like so:

So I traced the shape of the bonnet with vertices, keeping it lightweight and simple. I then 'Inset' the inner vent area (without boundaries) and it all seemed to be working fine. 

But from the tutorials I watched/read, I gather that I will need a supporting edge-loop around either side (so inner and outer of the actual extruded rim). As stated above the inner one 'Inset' worked great but for the outer one I couldn't use Inset, and so I followed some instruction video and used 'Knife Tool'. But now as you'll see in pic below, the edge-loop doesn't continue all the way around the edge I want it to. It in-fact only goes around the one corner  (pic:)


NOTE: Here is the correct one on the inside of the area... (NB. I'm new so not certain that even that is the correct way to make such edges in my models)..


ADDITIONAL: In trying to debug this, I notice the adjacent faces which I also cut with knife-tool are just registered as single faces still, this obviously what is causing my problem. (another pic...)


ADDITIONAL 2: I know see i could delete those faces and make two new ones in the place of the old ones. This has fixed the problem almost (ie. the outer side, of that outer-rim is now a complete separate edge loop). BUT - I still have issue where the loop carries through my junction on the X-Axis (note I have this problem on the inner edge and outer edge of the vent feature).... final pic attached here:


Any help hugely appreciated. Many thanks
In case anyone reads this in future with a similar confusion. The answer was that I had used 'F' to fill between the two vertices next to my knife cuts. But I didnt realise this didn't turn the one face into two. All I had to do was then delete them faces and make two there using the new edges. (hope that helps)