Penalties and interest

Hopefully this is the correct forum for these questions 

1. can I request to have tax penalty removed/abated? If so, how do I do that, what are the qualifications and how likely is it to happen?

2. I noticed in the list of interest rate on back taxes owed, the interest rate has steadily increased to the point where my balance owed is actually INCREASING in spite of my continuing to pay on the payment plan. Can this interest rate be negotiated down? These rates seem predatory.