If the pan keeps the oil away from the crank, more oil is never a bad thing. the more oil the more heat it can absorb, that is why race motors with dry sump systems that have no more than a quart or two in the pan, still run giant ten to fifteen quart tanks, more oil means cooler oil.
More oil means slightly cooler oil in a dry sump system; it doesn't mean cooler oil in a wet sump. It just means it takes a bit longer for it to heat up --- and longer for it to cool down. If you want cooler oil add an oil cooler, not a larger volume wet sump. And I've never seen a dry sump set up that didn't have an oil cooler as an integral part of the system.
Most racers who use "7 qt" pans don't run 7 qts - the name is a bit of a misnomer. They run 5 qts. and use the pan to get the oil further away from the crank to reduce windage losses as Rothfuss alluded to.
High volume pumps should be used on racing motors built with looser bearing clearances. If the clearances are larger, a larger volume of oil has to be moved in order to fill the clearance AND maintain appropriate pressures. If you use a HV pump with normal (smaller) clearances, all the pump does is consume additional HP to pump a bunch of oil around/through the pump's bypass. Higher pressure pump (or reset the relief valve) for high revving motors that need more pressure. High volume pump for larger bearing clearances to maintain pressure while moving more oil. Anything else --- just a regular ole pump with the relief set at 60-65 psig.