This is my new turbo set-up. No coolant lines run to this TO4S 60-1 that I just swapped with my stock s4 turbocharger. Since only oil lines are running to it, do I just plug off the coolant feed and return lines or should I run one line between them to connect them now?

Will either work fine? or is one recommended over the other?

 

Just plug them if your turbo doesn't need the coolant feed. FYI a split air blockoff plate fits perfectly over the coolant passage outlet on the LIM, you can use that to block off the feed, then just some cap/small hose clamp for the return into the waterpump housing.