TDMS implementation details

Dear Techies,

One of my client want to implement TDMS in their landscape. Database size is around 2TB and they have 3 systems Dev,QAs and Pro.

1) Is it to be implemented(New addon installation) in all 3 systems?

2)As per install guide 20 GB freesapce required, is it applicable for 3 systems?

3)What about the license cost?(we are on SAP 4.7EE SP1)

4)Can we have the option full QAS refresh(If any time) after implemnting TDMS?

5) If iam copying data from source to target(after implementation) is there any downtime required?

Thanks in advance

Nick Loy