Well if it doesn't, United will have a profit of £130+ million thanks to sale of Ronaldo. :P I think it does include transfers, but like you said, I'm not sure.
Its not that huge once you look at the scale. Everything's in proportion. I know my mum's still paying off the mortgage to our house after 25 years. So it taking 15 years for United to pay off a loan isn't that bad. Because the amount that has been borrowed is massive, as is the repayments. As soon as they cant afford the repayments things get a bit hairy.

