Few questions about vias and TLSconact center

[apazhe]

Hi,

I'm working on visas for me(tier 2 general) and for my family(wife and daughter).
I successfully completed all visa applications.
The questions are:
1. I create only one TLScontact account for myself and add wife and daughter into my group according (as I understand) the guidelines on page. Is it right approach?
2. My and wife have the same appointment time but unfortunately the same slot was not longer available for daughter. So here appointment time is 2h later. Can we still apply at the same time as family? Or we have to wait 2h to apply for daughter? Or we need to by "without appointment" service so she can apply with us?
3. I choose priority service and I believe it was "return by courier" checkbox as well(but I not sure). Total cost for 5y visa was 2005 USD which is around 1525 GBP. The visa cost should be 1220 plus 212 for priority which is in total 1432. So there are around 90 GBP paid for something. Is it courier? Way to much for it. Is there are any way to see what was included into the visa cost? All I was able to find is priority or not in form pdf.

Thanks a lot in advance