I'm having some trouble with two reports in the Advanced CRM Analytics.

Here is what I want to run:

1.) An average of how long unsold potentials have been in their current stage. So if a potential was converted from a known opportunity to a proposal 5 days ago, I want it show stage duration of 5 days. Right now I can only see a report that uses closing date, but that is giving us inaccurate readings as the closing date is the estimated date a potential will sell. Therefore I am seeing a stage duration for a potential that was changed to proposal stage 1 day ago calculated as 35 days (the closing date is 35 days from now). How do I fix this?

2.) I need to know how many potentials were changed to a specific stage over a relative period ie: How many potentials were changed to proposal stage in the last 7 days / month etc. I have no idea how to set this up :-(

Can someone help me? 

Thank you