
First, and probably least common, are the really old hive worlds. The most technically advanced, the ones with the biggest population. Where the world's enviroment is fucked up or nearly so, resources are either close to tapping out or have been tapped out, and everyone is crazy to one degree or another. These are Hive worlds in the "classic" sense, spanning from ealry (2nd-3rd) edition and resurrected in 5th.
Then you have the "interim" hive worlds. They have smaller populations (tens of billions mayhap) but will have something resembling a viable enviroment (people can go outside with gas masks) - Hydraphur fro the Shira Calpurnia novels and Verghast from Necropolis are examples here. Alot of "hive worlds" from the FFG RPGs also qualify here, as do the numerous novels and spinoff sources (Battlefleet gothic and the like.)
A subset of this are "smaller" hives on planets that are uninhabitable on the surface and below ground (Tallarn and Krie
The last category we might consider are "pseudo hives" or "proto-hives". Places that may have hives but not neccesarily the "staggering" populations. Forge Worlds and industrial worlds, mining worlds, heavily industrial or urbanized Civilised worlds, etc. Populations may be in the billions or even millions and the planet may or may not be habitable. It may even be placed on moons (Eg mining/industrial worlds, and some forge worlds.) We know from Battlezone Cityfight that hives usually evolve from other world classifications (and may cross over into them). These are hive worlds in the loosest sense of the word.
Food is.. up for debate. On one hand you have the common blurb about how Hives need food to support their populaces and without which they (eventually) starve. A good example being Orar from Battlefleet gothic (had a population of around 80 billion.)
Then again you have places like Necromunda, which has an order of magntidue more populace than Orar (by any estimate) but can support a massive (billions or more, close to or exceeding the population of the upper classes of The Hives) populaton on the underhive ecosystem alone (rat, snake, etc.)
And then there are those who continually reclaim and recycle anything organic in the hives (including dead human bodies) for food or water (good old corpse starch) like Stalinvast in Inquisitor. I imagine other planets may have hydroponics or similar technologies for food growing to at least supplement supplies. Or orbital farms.
The other key thing (for an industrial world) is going to be resources. If they don't have it on the ground or in orbit, they'll need it imported. (many of the older ones do to support the highly specialized and massive industrial infrastructure they have, like Necromunda and Armageddon)
Anyhow, the big factor is going to be what sort of FTL ships (if any) the Hive World has or can build.