you've missed the point completely. United as a club and a business generate so much money the interest payments on their loan is very very affordable.
Liverpool as a club and a business does not generate anywhere near the same level of money and therefore cannot operate with a debt anywhere near Uniteds
The rules are the same but you are trying to compare two clubs or businesses that are miles apart in terms of the cash they make. It has nothing to do with the owners either. If anything Uniteds owners, the Glazers are worse than FSG beacuse they take money out of the club. FSG don't!!!
FSG aren't the problem here. You need to look way back to the beginning of the Premier League. United embraced the market and media concept the PL brought. We sat on our hands.