Michael's debt was already taken care of even before his death. In 2007 he had all his earnings for the ATV catalog go into paying down his debt. By the year 2011, he would had been completely debt free, so that was not a problem. The problem was that Michael was cash poor, so he did not have alot of liquid money to spend. However, he was never in the financial trouble that people are saying he was in.
Also, he wanted to keep Neverland for estate purposes, however, his manger at the time, Randy screwed up. While Michael was in the Middle East, Randy and his goons ran Michael's estate into the ground and did not pay Michael's bills. That is why he got sued so many times in 2007. It had nothing to do with his debt. Randy did not pay to keep up Neverland or to keep the employees paid.