i've seen some turbo setups that relocate this hose.
i assume its used to feed coolant to the turbo, then from the turbo goes back to the thermostat area.

i just wanted to know if anyone can confirm this for me.

if one wanted to replace/remove that metal tube, is it just a matter of running a rubber hose in its place?

 

the only way you can remove that tube is if you relocated you oil filter, that tube is the coolant for the oil cooler, you can replace it with a rubber one if you wantted.

 

...so can i not relocate the filter, but use a rubber tube?