These are genuine questions because I don't understand everything either
Also, you could define a maximum file limit size, and at that point your phone would be considered backed up, and then if no other route is found, the transfer is cancelled after a certain timeout.
That is only a software bug.
Heartbeat pings to contact list, cached at senders end until recipient is ready and offer aliased nodes as a feature so multiple devices can act as a RAID array for an identity, both at senders end and recipients.
The video will be on the sender's device until the recipient confirms that they have received a 100%. So this prevents a phone storage clogging situation.
> The infrastructure forces my phone to instantly download the content, because no one is paying for storage of it before it gets routed to me right?
Yeah, that would be accurate. There could be intermediaries that charge low prices to cache snaps for you so you didn't have to download it ASAP, but that would negate the ephemeral nature built into Snapchat)