You will not go wrong following the overhaul manual and subsequent SBs exactly. The main bearings will not spin. Do not over think this.
As for the sealant on the oil pump gear cover I've done it both ways. I would only use the thinest amount of sealer on the outside of the pump housing if I used it at all per the SB.
Lets see if I can describe this right. The oil pump does not rely on extremely close tolerances and a seal to work sufficiently pumping enough pressure to these engines. This is not to say you want to assemble and run one that does not meet the tolerances. Ask yourself this. What is sealing the drive shaft around the cover. No sealant worked fine for years until they wrote the SB and still will.
Oil pressure loss it woulds seem is rarely the fault of the wear of the oil pump but rather worn main bearings to a point that exceeds the pumps capability. This is kind of a built in warning in that if you have low oil pressure it's more than likely time to replace the main bearings and or crank. Unfortunately I'm speaking from first hand experience.
CAUTION - My forum posts may be worth what you paid for them!
Bruce Fenstermacher, President, TIC170A
N7A '49 170A -More original than most making folks GREEN with envy
N42532 '45 J-3 Clipped Wing Cub