I agree with most of the comments on here. However, I don't see a lot of responses to the OP's questions. Wish I could help, but this isn't something I have tried to do before.
I have a new driver in the house and understand the OP's concerns. Fortunately, my son seems to be a better driver with the manual Porsche than he is with the automatic SUV and I don't worry about him driving it. I was scared to death early on though.
Not sure it is helpful, but here is a link to a discussion about switching the other way.
converting an automatic to manual? - Rennlist Discussion Forums