1. Seller Feedback is a feature in the program. Buyer Feedback there is not. The leave feedback link is shown on a user who has posted an ad. That is a nice suggestion for a future release. There is a feedback link in users profiles.
2. HMM interesting I will test that out and let you now if I see anything. I have an active beta 5.0 up so it should not take long to see if there is an issue.
3. This is probally related to the cookie perpage which may be tied into the above issue. I will see.