Rank by cash flow and you've got a pretty good proxy to measure the order of who is, or who should be concerned about FFP.
However this is based on dated information (2010-11 financial statements) and the picture might be very different for some clubs now. We don't know for sure, but for example Chelsea turned a profit for the first time in years, so your concern might be a little more relaxed, and we all know our wage bill has come down dramatically in the last 12 months or so.
On the other side QPR are not listed here and may not be in danger of qualifying for Europe, but will still be subject to the domestic version of FFP whatever that is, and we all know they've been spending like drunken sailors and I can't image they have a huge income with a gate of less than 25K per match. I'd also be curious on where Spurs are right now. This report shows them very healthy; however they've been spending like a CL club for the last several seasons, but have not got the CL income each and every one of those seasons.