YouTube is not really suitable for a Bible study such as this. It's geared more toward video, which you do not have, so it is in your best interests to use a method that is designed more for audio.
You already have server space offered to you (and which you have been using from the beginning) which you are quite welcome to use and I know the host sees no issue with its presence there. You may as well use that, since it already exists. I realize there are a number of people being petty and immature about this, but you already have a space to host the recordings. Don't expend effort looking for a solution to a non-problem.
Putting them on iTunes is a good idea though.
Limiting the Scripture reading to smaller portions is good. There are some passages that you could spend hours going over if you wanted, and you'll be forced to dilute discussion if you focus on too much at once. (The opposite problem also exists.) As another who has led a private Bible study for several years now, I also know it's preferred when people come having already read the passage for the week, so they are better able to contribute toward any discussion. This is somewhat unenforceable though, so it's just something you'll have to stress outside the study whenever possible.