Developer here.
This is actually a very very cool idea. Is this
a reddit product?
a user bot with the blessing of reddit?
an independent bot like anybody could write a bot?
Who are the people behind this bot?
Not a reddit product, just a bot made by a reddit user.
What is their measure in case reddit cancels this?
If reddit cancels this I will probably make a new system for withdrawals only.
Whom can I slap if the hot wallet password "accidentally" gets too accessible?
Yourself. Don't deposit more than you're willing to lose at this time. There is no warranty, insurance, or guarantee of any kind.
Edit: This should just as well work on twitter!?! and if done by the same people, transactions between twitter and reddit could be free.
This was inspired by the twitter version btctip.com. I've used it and was impressed. That is run by someone else.
Edit: So for $5 I may get my money back in case the service is terminated?
With my money in my own priv key the service makes a more reliable impression to the whereabouts of my money (no fractional reserve) but it's ultimately less secure (100% hot wallet) and costs fees to send between reddit users.
Not so much if the service is terminated, more like in the event of downtime be it with the bot, blockchain.info, or reddit itself.