Is it normal for the orange cables in my auction EV to tick and feel warm after a drive?

That clicking and ticking after a drive is almost always the thermal management system doing its job, not something broken. When you park after driving, the battery cooling loop keeps running for a few minutes, and you're hearing the coolant pump, valves moving, and contactors or relays switching as the car manages the pack temprature. EVs don't have an engine radiating heat, but the battery, onboard charger, and drive unit all need cooling, so the car keeps churning away after you walk away from it. If it settles down within a few minutes like you describe, that's exactly how these cars behave. If it ever clicked nonstop for half an hour or you heard grinding or whining from that area, then I'd worry about a pump failing.

That warm cable feeling is probaly just the main busbar doing its job under load. You can tell it's working when it's hot, but if it's just warm, that's normal resistance from high current flow. At my shop, we've seen that when a power unit pulls 350 amps, the surrounding conduit heats up significantly for the whole run. Since you got the car running, the main focus should be monitoring the DC-DC converter output; a subtle drop of even 1 volt there often indicates a stressed connection before anything melts.

The fact that you mentioned encountering initial error codes and a dead auxiliary voltage system is significantly more pertinent than any concern regarding the post-drive thermal acoustics. In my expirience with these fleet vehicles, persistent phantom faults often trace back to poor grounding or a failing Battery Management System, which can be misinterpreted as a component failure when it is merely an underlying electrical instability. I highly recommend checking the specific codes against known module failures, particularly focusing on the low-voltage DC-DC conversion path, before assuming the complex system operation is entirely nominal.