You don't need to do much with RAM - just enable the XMP profile and it'll set the correct timings for you. I only upped the voltage a teeny bit as for some reason, that seemed to help me with stability.
Yes I'm watercooled and de-lidded... the CPU has it's own dedicated 480mm rad.
It's overkill, but means I can run the fans and pump at their lowest setting... even under load they don't need to spin up.
I run the CPU at 5.2GHz 24/7, don't let it cycle down... with that and my low fan/pump speeds, it idles around 40C. Under load it's 55-60C. Gets lower if I spin the fans & pump up... but I like having my system as close to silent as possible & this is almost inaudible.
On air, I'd be ok with load temps up to 75-80C.