I'm going to have to respectfully disagree. The T25 is a conventional bearing turbo, and Mitsubishi engineers did not run water lines to the turbo for fun. Turbo manufacturers don't include coolant inlets and outlets in turbo center sections for fun either. In my opinion, they are there to be used. There is a thread on DSMTuners in which one of the moderators removed the water lines from his T25, and grenaded the turbo a couple of weeks later because of it.

This isn't to say that you can't run low boost without water lines without blowing your turbo, but if you plan on boosting hard and often, like most DSMers do, you should have water running through the turbo to pull unnecessary heat away from it. Just like turbo timers let oil run out of the turbo and cool down without baking in the bearing journals, water lines generally cool the center section and maintain an operating temp that will lengthen the life of your turbo.

In the end, coolant lines aren't that much of a hassle. You hook them up, and then they just sit there. Mine will remain intact