I just bought a case of Omega 10% and it says on the bottle "do not to use after run oil with this fuel" and that its already been added to the fuel.
if I do add any lube to my engines for long term storage its air tool oil,it keeps any rubber parts supple and prevents seals from drying out.
as for rust living 3blocks from the beach you would think it might be a problem I have noticed some minor surface rust but nothing internal at all.