I think this is all good advice and I hope some of it helps.
As for the clothes, you'd be surprised what you'd find at the clearance racks, thrift stores, goodwill, ect. You don't have to get alot. Just a few things and keep under a budget.
One thing I forgot to mention however is to also get hooked up with a trans support group. I'm with trans-central Pa. They can be a HUGE help. Specially with the parents. I know we usually have a therapist who attends, just to give advice ranging from recommended doctors, parents, and more. One of the things I like is that during the meeting she will take people like parents, loved ones, ect off to another room to talk to them about the TG in their lives. It can be very helpful.
But I would agree that a job or school is something that is a must. While it would be nice if your parents would pay for things for you but you shouldn't rely on them. By doing so, would show them that you are being mature and working for it so they maybe more open to it. Plus it would take a lot of the stress off of them. just my own opinion.