Over here it just needs to be secured by two brackets. It's not going to remain exposed either, once I'm done with the shakedown the pod will be getting covered and I'll make up some custom heatshields for the manifold and dump.
As for oil coolers/filter relocators, I would imagine that as long as your fittings and hoses met the relevant AS for pressurised fluid couplings (no idea what that is) and as Rolls mentioned, the installation isn't dodgy, there shouldn't be an issue?
That is really the main thing that I have found with modifying cars, if you do it properly - and it shows (quality welding, well thought out mods, no dodgy corners cut) then things will generally go a lot easier for you.