The metal you see is just part of the connector and is tied to chassis ground, as this JonnyGuru inside view of another OCZ power supply shows, so it's safe:
I probably wouldn't bother replacing or fixing that socket, provided it's not cracked around the lugs or the rim. OTOH I wouldn't plug and unplug the AC cord more than I had to with it. If you know how to solder and feel like repairing it, you want an IEC connector, type C14 with solder lugs on the rear (not bottom) , snap-in (not screw-on), something like this:
Most of these are made of plastic that will melt if the soldering iron is held to the lugs for too long. It may be easier to solder the socket through the hole in the PSU case, before snapping the connector into the hole.
This component handles high voltage and comes before the fuse, meaning the fuse won't provide protection if something is wrong with it. Also incorrect wiring here can create a high voltage shock hazard, potentially lethal. Those two little blue disk capacitors are for filtering out noise and have special safety certification because they're connected directly between high votlage and chassis and have to be safe even if an ungrounded AC outlet is used. The boxy yellow capacitor on the left (enclosed in black heatshrink) is also a noise filter. Notice the dab of silicone rubber sealant to hold it in place and the Teflon tubing over its two high voltage leads.