I've been toying with the idea of using Lugia in a Weather team. With the inclusion of Hurricane, i wanted to use Lugia in a Rain team. Now that you mention it, Life Orb does go against Lugia's Multiscale.
So i guess i could revise one moveset as:
Hurricane
Thunder
Calm Mind
Roost
Aside from Leftovers or berries like Sitris berry, I'm not sure what other items would work well for Lugia.
Leftovers would definitely be the item for something like this.
The main problem here would be that both of your offensive moves heavily rely on rain being active and Lugia has no way to start it.
Boosting with Calm Mind takes turns and rain will run out by the time you are ready to attack with a boosted Lugia.
Especially in Singles where you can't partner Lugia with something that provides the rain next to it.
The other problem is that Flying + Electric is mediocre offensive coverage at best.
Hurricane is the powerful STAB, okay. 70% accuracy is horrible and Aeroblast would most likely be better here, but you want to use it so it is what it is.
Thunder doesn't really do anything for you though besides give you style points for running it with rain. Boosted Hurricane should be sufficient against most Flying- and Water-types, which aren't the biggest threats to Lugia anyway.
Electric-types on the other hand resist both of your attacks and can hit you for serious damage with their STABs.
Replace Thunder with something that works outside of the rain and at least does decent damage against Electric-types imo.
All of this is completely from a just for fun perspective. From a competitive standpoint, none of this is ideal.