Each video has a comments section, and some of the early videos did get the types of comments you're talking about. I put the answer on the comment page and (in some cases) updated the videos. But I updated the README in the repo and improved the videos, and it stopped being an issue pretty early on.
Now all I get in support requests is the occasional account management email, and those are pretty streamlined at this point. (I could eliminate nearly all of them by creating a proper account management page, rather than directing people to email me, but given the number of requests I get, the cost of doing that is way higher than just handling it by email.)
It helps that the screencast is aimed at more advanced developers. But that's also why it didn't end up being viable in the long term, I think. That and the "long play" format, I suspect.
Now all I get in support requests is the occasional account management email, and those are pretty streamlined at this point. (I could eliminate nearly all of them by creating a proper account management page, rather than directing people to email me, but given the number of requests I get, the cost of doing that is way higher than just handling it by email.)
It helps that the screencast is aimed at more advanced developers. But that's also why it didn't end up being viable in the long term, I think. That and the "long play" format, I suspect.