I like an argumentative new poster....
A transmission cooler and engine oil cooler are the same. Transmission fluid is oil with a different additive package. A liquid cooled engine does maintain a fairly steady ambient running temperature but does little to cool the oil which is in the sump or in the remote tank (in the case off the Rocket), away from the coolant. The Rocket has underside piston crown oilers which add even more heat to the oil as the oil cools the piston crowns. It's a proven fact by independent testing labs that reduction in oil temperatures prolong bearing life and oil degradation. While an oil cooler isn't a mandatory item (if it was, triumph would have incorporated one in the engine design), the addition of an auxiliary oil cooler will do nothing detrimental to the engine. It will in fact allow the engine to live a longer life. Another advantage to adding an oil cooler is that you actually increase the static oil capacity. As far as leaky fittings, maybe a hose with a worm clamp leaks but properly double crimped stainless lines and quality Weather head AN fittings never leak and never will unless they are installed improperly.
You need to get out (when it gets warm) and experience the heat from the engine and then report back on your synopsis.
Having a potato bike, I'm sure you heard about stuffing your bag of gut busters between the jugs to keep them warm on the way home....On the Rocket you can cook your dinner.