I'm happy with"direct or consequential damage" - thanks, both of you.
As regards the other phrase, "compound interest rate" may be appropriate - it relates to the basic interest rate plus the spread (περιθωριο). Would that be a normal way to refer to compound interest in Greek? (Eurodicautom gives "σύνθετοι τόκοι" or "ανaτοκισμός".) Maybe it would be better just to leave it as final interest rate and assume an economics-minded reader will understand how it is calculated!