What would everyone else in the Premier League, La Liga or Bundesliga compete for? Half the league may as well not bother with the second half of the season if the only prize is the title. I don't know about most people but I'm not that fussed about watching Partizan Belgrade, Nordjaelland, Debrecen, Maribor or Bratislava in the quarter finals. By all means, 'dilute' it down if it means Barca 12 Nordjaelland 0 isn't the usual quarter final aggregate result.
The Guardian in their season review suggested a play-off for the last champions league spot. That would be interesting.
Fourth place should get you a place in the Europa League at best. Top two in Champions League with FA Cup winner, then third place, then League Cup winner. So fourth would only get in CL with someone winning two competitions. Would sort out the FA Cup as well if that was the prize for the winner.
well someone here suggested we have an open top bus tour to celebrate avoiding relegation. Now that's truly sad.