If you had a clean sheet of paper how would you restructure European football in general? (Putting aside the unlikeliness of it from a red tape perspective)
Perhaps a European premier league system of 25 teams in the 1st division and 25 in the second division with relegation systems etc.
Problem with UEFA is that they generate over US$3bln in revenue and the prize money as a percentage of revenue is very small. Clearly very inefficient.
1st you need to take the competition away from governing bodies like UEFA, clubs should run it themselves. Other than that current system looks decent. But I would still make changes:
-domestic leagues should be smaller, less games, creating room for more international games. Say, a 14 team, 26 round system in the top 5 leagues. Also eliminate league cups, pointless. And reduce domestic cup competition so the top league clubs play up to 5-6 games if they reach the final (no repetition games, that's stupid @FA)
-more international games, so make the group stages with more teams. Or make it one league/2 groups with many teams rather, where everyone plays everyone. Then start the 2nd phase from a QF.
-additional rule I'd introduce is qualification to european cups through a 3-5 year period. So you don't get to qualify after a fluke good season, or benefit from a fluke bad season from a top club. You need to consistently do well over a longer period to get into a euro cup. I'd personally make it more even, so more champions and less 2nd, 3rd placed teams enter into a CL, but that's impossible now with how much money those richest teams generate
-reduce NT games. No one needs pointless friendlies between Norway and Mongolia in March, when Dortmund plays a CL QF right after and risk losing their starting CF. Also reduce qualifications. You don't need to play Vatikan or San Marino twice in a qualification round. Reduce the groups by eliminating those garbage teams before in a knock out pre-qualification. Make the actual qualifications with 3-4 team groups. Make the Euro 16 teams max. Make the world cup 32 teams max. Remove nations league and confed cup.