Is it a problem that I have metal studs in the walls?

Metal Studs are no problem, our insulation is a full 16" wide so it will fill the entire cavity. The only difficulty you may experience during installation is metal studs don't tend to "friction fit" the way wood does so you will need to use some insulation hangers ("lightning rods" or the self-adhesive pin/washers) to support the insulation til you get the finished wall on.