The support plan selection

Hi, 

My partner has questions about the support plan.

Q1: What's  the difference between these two support plan?

Q2: They have two register accounts, they could only open ticket for the old one. But all their services are connecting to the CSP account. 

      a) old accoount

      b) New CSP account 

When they open case, there was only old account available for choose. Does that affect anything?

 

Thanks