If you have or have access to a welder, I suggest you patch those spots. I had rust in the same spots and they are an easy repair. You wont have to pull the fenders, although it makes work easier. On the outside of the inner fenders there is a steel plate,( where the hinge bolt goes in ) held in place by some bent clips. Take it out and start cutting the bad material. There are 2 layers of sheetmetal there. In my case the part holding the plate wasn`t gone, so I just had to fix the part in the enginebay. Piece of cake, but its a bit more work if you have to patch the outside with the clips. Either way, take measurements of the location of the hole before cutting.
Same story at the rad support. I just had to repair the layer inside the enginebay... I did blast the area underneath before welding it up again though.