It is my understanding that hive mind are just like every other race except they have less features.
They can't have pop from other empires, they have a special ethic and they have no factions or happiness.
Are they meant to be a simpler play style or am i missing something?
The tripple choice of Ethic/Government/Trait was propably made to make the quests more capable of checking for them as special case. Some check on Ethics (where Hivemind is exclusive), some on Governments, some on Pop Traits. And this way they have something on every level to check. (Priates would check on Government, Environmental Adaptation on Pop and most quest choices check on Ethics).
Thier weakpoint is that they will abysmal Influence income, from not having factions. And no production bonus from Happiness.
"Every mechanic dodged, is a mechanic you can not master."
It was often demanded. And now some basic approaches are in.
With the "Nerve Stapeled" and "Hivemind" Traits in the game (wich disable happiness for Biological Pops), we should be able to mod in our own interpretations of Hiveminds.