Interesa demado. Thanks for the excuse to look it up.
To be short, homo is (kompreneble) a long entry, homeco is defined as "human-nature" (not what I would have guessed either). Whereas humana = "humane".
Noted other affixes you may find useful:
Homarano = "Citizen of the world" (really, I have three dictionaries saying that)
Homizi = "To man (a gun or a boat, etc.)"
Homama = "benevolent, philanthropic"
Homamaso = "Crowd, populace"
*Homevit(em)a = "Unsociable, misanthropic"
Nu, tempo por homizi la laborejon
I don't know the parts of English reasoning, but 'the humanity' is used to refer to something horrible, or 'the humanities' as a field of study. 'Humanity' is used alternately with 'the human race'. This might help: