Language Of Confusion: Guest Hosts

It’s almost that time of year, when we’re inundated with guests. Not me, though. Thankfully. Anyway, etymology.
 
Guest comes from the Old English gaest/giest, which just means guest or host. That’s from the Proto Germanic gastiz, which is from the Proto Indo European root ghos-ti-, stranger, guest, or host, and in spite of looking like ghost, no, they’re not related even a little.
 
But you know what is related? Host, which showed up in the thirteenth century. Except that came to us through the Old French oste/hoste, guest or host, from the classical Latin hospitem, a guest or stranger, from the word hospes, host. That one’s thought to be from the Proto Indo European ghos-pot-, literally “guest master”, which is derived from gos-ti-. So basically, Latin dropped the G and now we have host.
 
And I’m sure you noticed how hospitem looks an awful lot like hospital. Hospital itself showed up in the mid thirteenth century meaning a shelter for the needy, probably because there weren’t any hospitals back then. It’s from the Old French hospital/ospital, a shelter or hostel, and also the origin word for hotel. And yes, that’s where hostel comes from, too, and weird fact of the day, use of hostel died out in the sixteenth century only to be revived in the early nineteenth century. So the Old French hospital is from the Late Latin hospitale, an inn, and that’s taken from the classical Latin hospitalis, which is from hospes, like host was.
 
Next, how about a negative word from the same place. Hostile showed up in the late fifteenth century, coming from the French hostile, and before that the classical Latin hostilis, a hostile or enemy. That’s then from hostis, stranger or enemy, another word from ghos-ti. I guess because strangers were generally considered to be enemies?
 
Sources
Online Etymology Dictionary
Google Translate
Omniglot
University of Texas at Austin Linguistic Research Center
University of Texas at San Antonio’s page on Proto Indo European language
Tony Jebson’s page on the Origins of Old English
Old English-English Dictionary
Orbis Latinus