Can any of my interest or penalties be waived?

The short answer is No.

Chapter 60 section 15 of the Massachusetts General Laws sets forth the interest and penalties
for excise taxes.

The following interest, charges and fees, and no other, when accrued, shall severally be added to the
amount of the tax and collected as a part thereof:—

For interest, as provided by law, excise is 12% per year.  

For each written demand provided for by law, not more than $30.

For the issuance and delivery of a warrant to an officer, $10.

The collector may, in his/her discretion, waive such interest, charges and fees when
the total amount thereof is $15 or less.

Once a warrant to collect has been issued the minimum would be

$5.00 Demand (minimum demand charge)
$10.00 for the preparation of warrant
Interest on the unpaid tax

This would be a minimum of $15.01 and over the amount by law that could be waived. Making it
illegal to waive the charges once a warrant to collect has been issued.