My wife and I owe about $15,500 in 1040 taxes from years 2005-2015. We didn't file from 2010-2014. We had a total of about $6,200 in refunds due in 2010, 2011, 2012 and 2014 and believed whatever refunds we had coming would offset some of what we owed when we eventually did file. I had talked to the IRS in 2011 to set up a payment plan for 2005-2009 and then never followed through. They sent us letters for about 6 months and then we stopped hearing from them. My daughter is wanting to apply for financial aid so a few weeks ago I called and spoke to an IRS rep and she told me the time to claim our refund for 2010 and 2011 ($5,700) had expired. She instructed me to file 2012-2015 and that I needed to include a check for everything we owe (2005-present) or a 9465 for the years that we owe. (I also filed 2010 and 2011 just so they are on the record.) Using the amounts from the 433f instructions, I ended up with a $28 monthly deficit before my tax payment. Not thinking it would ever get accepted, I put that I could pay $50 a month on the 9465. A few days ago I got a notice that they approved the $50/mo agreement but it's only for tax years 2005-2009. 2013 and 2015 ($2,750) are not included in the agreement even though I put 2005-2015 on the 9465.

A couple days after I got the notice of approval on my $50/mo payment plan I got another notice that a $12,200 tax lien has been filed for tax years 2005-2009 (the same years covered by the payment plan). The notice says it's for 'personal property' and doesn't say anything specifically about bank accounts or wage garnishment. I don't recall ever getting a notice of intent to file a tax lien. If we did, it certainly hasn't been within the last couple of years.

I have several questions:
1. Since the payment plan is not what I asked for in terms of the years I wanted included, can I reject it or appeal it?

2. Because I have a $78 monthly deficit with the payment agreement, can I petition for "uncollectible" status even though I have already said I could pay $50/mo?

3. Why was a lien issued at the same time a payment plan was approved?

4. Is there any point in appealing the lien? Is this approach ever successful?

5. If I start making the payments, can I still submit an OIC? What's the lowest percentage they will consider? The letters I'm getting from lawyers seem to indicate they can get it down to 5 cents on the dollar.

6. Is the 10 year collection statute affected (tolled) by an active payment agreement?

7. Even though the lien notice I have doesn't say anything about bank accounts or wage garnishment, are these things automatically included or is there a separate process they have to follow to garnish wages and attach to bank accounts?

8. Is there any way to negotiate the $5,700 in unclaimed refunds from 2010 and 2011 into any of this?

9. Other than how I got myself into this mess and how to prevent it going forward, are there any other questions I need to be asking or any other rights I have in settling this tax debt?