itch.io

Not sure but I think when you get a game for free on here you only get access to the download and not any key pool. Would seem to make sense to me because then the keys would get abused and exhausted otherwise.

Way to spoil it for others

If you claimed the game for free (as per the current special promotion) a Steam key is not available  (DRM-free download only) so you have to make an actual purchase to get one, which is totally fine as far as I am concerned.

Any chance of getting a Steam key with a purchase here on Itch.io??

If you have privacy concerns that's one thing, but it was another entirely when you said (and I quote) "it wants me to let Itch take over my Steam account and steal my info", which is complete and utter nonsense and is only something someone would say due to ignorance of not understanding what openID is or how it works. If you don't want to do it because you are overly paranoid that is your prerogative, but it is a requirement if you want to be provisioned a Steam key for the game from Itch.io.

You don't seem to understand what openID is. It's not trying to steal your info and it will never have access to your login credentials or anything like that. It is perfectly safe. If you look in your account settings here under 'Connected Accounts' it says the following:

You can connect accounts from third party services here.

Steam

A Steam account is necessary to claim Steam keys from your purchases where available.

BTW. Humble is giving away steam keys yes... But these keys have to be claimed on Steam accounts, so there is no option for resale.

 There may be a warning message on the Humble giveaways and the key will disappear from the page after the stated deadline, but once you have the Steam key in your possession it will generally continue to work even long afterwards and for the foreseeable future. It's rare that the Steam keys themselves actually expire.

What did you honestly expect? Once news of a game giveaway ends up in feeds, forum posts, and places like Reddit communities there is going to be a flood of people coming, especially for a game that looks to have some actual real production quality to it. I can certainly understand your concerns but you are incorrect about Humble not giving free Steam keys... they do all the time.

Anyway, like someone mentioned in another thread a way to do a giveaway without distributing keys is to use the functionality that exists in the Steam API (Oauth??) to redeem an activation key directly to a user's Steam account with their approval. Using this method the game can only go directly to their account and they will never see any activation key.