I think you could get a little closer, but close like 1 foot might put too much heat on the plastic and start to melt it. If you warm up adhesive just enough it will usually allow you to pull the part away from its bond. Also don't stay on one spot for too long or you will damage the plastic.
Are the 2 pieces of plastic on the front of the case what is keeping the panel from coming off? It seems kinda odd that they would do that, you sure there isn't any hidden screws holding it in place? It could also be riveted from the inside like my Antec Sonata case. Also if you really wanted to, with a little effort you could use a hole saw to cut circles out of the side panel to install the fans.