Another important question..
did you take off the sump when welding that oilline?
why i am asking this is that maybe if you didn´t the oilpump may have sucked in some metalshavings..
NOT GOOD !!!!
And about the heat..
you should have pressure anyway.
the oil in the oilline to the turbo are already under pressure.
so it shouldn´t matter.
the overall raised temprature should been taken care of with the oilcooler.