Hop on ls1 tech under the ls4 section contact either x11 nut or 08pimpalass there both in the Florida area where you are and can get you the help you need.
As for your engine codes I would check your fuses and relays. Something isn't right. And it just so happens those wires all run together. As for your engine mounts....replace them ......replace them...replace them. Lower rear and front. They are very weak and tear apart easily with age. Clicking noise might fix itself after you square that away
