Planning Poker - the problem continues…

Sorry guys still I didn't find sufficient answers to post here for the previous post I posted about problems when playing Planning poker.. I will provide answers once I find some good and logical explanations..
Now I have a new problem…. There you go… :
When Playing planning poker the team express ideas in front of the product owner to come in to a conclusion about the weight of user stories, clarifications, etc.
We do not have programmed robots in our teams to have same level of knowledge and skills. Though SCRUM is for good for good developers, ( Or even Software development is good for good developers according to Ken Schwaber - SCRUMforTEAMSYSTEM) in reality we get a mix to our teams..
So after observing the discussions going on …there is a product owner who says… Look I don't want guy X and Y in this team.. I need another like guy Z instead of X and Y . then we can burn down the back log more faster in sprints.. You guys agree to burn down only this amount in this sprint because your guys are not experienced. In traditional Project management what we do is we colour all our user front ending with really experienced and good guys and get the project delivered some way or the other. In SCRUM as we produce this much of transparency, Anybody who faced this issue and could you please explain how to overcome this issue..?

Problem I faced with Planning Poker

I copied this cartoon from www.implementingscrum.com.. Im a cartoon freek.. and thrilled to see SCRUM in cartoons...:-)

We played planning Poker for the 1st time and following are the problems I faced.. I will find the answers for these questions from experts and post them here later..

1. When Moderator reads 1 story we kept playing Poker and came out of an estimation to that specific story., But when we went through the PB more and more., team wanted to revise the previous story estimates again as its a comparative thing., How do you handle this situation?
Do you get the team to analyze the PB before coming to Planning poker so they will be more or less accurate with their comparative guess with other user stories in the rest of the product backlog?

2.There was one user story which we had to purchase some device for that. Scrum master ask where do we do the procurement management, planning , Cost estimation etc, Will SCRUM has some guidelines for procurement management for the project.

3. Customer who acted as the product owner didnt have answers for some of the questions.. there were situations such as I need to check with my infrastructure guys.. I need to ask my BI manager etc. How do you tackle that situation?

4. for certain stories we felt that we need the use cases or further analysis before thinking of their weight. ..

5. Looking at from the Project Office I saw many team for many projects they had different type of assessments. As an Example., same story "User needs to log in to the site and fill the registration form" was rated by the Team A as 5 and Team B as 20.. so how do I compare and see each team performance from the top when I look at my teams product burn down charts?