On the subject of Latin plurals, I wondered what the plural of locum is a while back.
Singular: Locum tenens
Plural: Locum tenentes
Locum is just an abbreviation.
I like Pinker, if you do too, this and this are a good read.
On the subject of italics, this is a good quote from Attwood:
I didn't say she stole my money.
I didn't say she stole my money.
I didn't say she stole my money.
I didn't say she stole my money.
I didn't say she stole my money.
I didn't say she stole my money.
I didn't say she stole my money.